R v Quist - [2025] SADC 35

DISTRICT COURT OF SOUTH AUSTRALIA
(Criminal)
R v QUIST
Criminal Trial by Judge Alone
[2025] SADC 35
Reasons for the Verdict of his Honour Judge Allen
4 April 2025
CRIMINAL LAW - PARTICULAR OFFENCES - PROPERTY OFFENCES - ARSON AND LIKE OFFENCES
CRIMINAL LAW - EVIDENCE - MATTERS RELATING TO PROOF - STANDARD OF PROOF - CIRCUMSTANTIAL EVIDENCE - GENERALLY
The accused elected for trial by judge alone on one count of arson, contrary to s 85 of the Criminal Law Consolidation Act 1935 (SA).
It is alleged that on 23 December 2013, at Parafield Gardens, the accused knowing that she had no lawful authority to do so, intentionally or with reckless indifference, damaged by fire a shopping centre, the property of LJ Hooker Commercial Adelaide Pty Ltd.
Verdict: Not Guilty
Criminal Law Consolidation Act 1935 (SA) s 85(1), referred to.
Shepherd v The Queen (1990) 170 CLR 573; R v Hillier (2007) 228 CLR 618; Edwards v The Queen (1993) 178 CLR 193; R v Baden-Clay (2016) 258 CLR 308, considered.

R v QUIST
[2025] SADC 35
[Criminal]
Introduction

On an amended Information dated 6 July 2015 (amended 2 March 2021), Ms Quist is charged with the following offence:
Statement of Offence
Arson. (Section 85(1) of the Criminal Law Consolidation Act, 1935).
Particulars of Offence
Shilane Quist on the 23rd day of December 2013 at Parafield Gardens, knowing that she had no lawful authority to do so, intentionally or with reckless indifference damaged by fire a shopping centre, the property of LJ Hooker Commercial Adelaide Pty Ltd.
The accused elected for trial by Judge alone. These are my reasons for finding her not guilty of the offence.
Overview
The accused is charged with one count of arson. On 23 December 2013, some time prior to 5:15pm, a fire was deliberately lit inside a disabled toilet near one of the entrances to the Parafield Plaza Shopping Centre on Salisbury Highway.
The accused’s mother operated the Australia Post shop in the shopping centre.
The fire was contained to the disabled toilet due to the quick action of three employees from the Foodland supermarket within the shopping centre, who sprang into action and extinguished the fire prior to the Metropolitan Fire Service (MFS) and police attendance.
The accused was badly burned in the fire and was taken from the scene by an ambulance to the Royal Adelaide Hospital (RAH). She spent a number of weeks in hospital recovering from significant injuries.
The accused sustained burns to just under 24% of her body, particularly to her arms, hands, feet, face and neck.
General directions
It is not necessary for a court having conducted a trial by judge alone to set out the standard and obvious directions of which a judge is bound to be aware. However, I remind myself of the following matters.
The accused is presumed innocent unless and until the accused guilt has been proved beyond a reasonable doubt. This requirement extends to proof beyond a reasonable doubt of every element of an offence. It is not sufficient for the prosecution to show a suspicion of guilt or to demonstrate that the accused is probably guilty. In making findings of fact, I must rely upon the evidence given by the witnesses and contained in the exhibits.
Expert witnesses
In this case, expert witnesses Sergeant Jason Wynne, Dr Duncan Taylor and Mr Simon Cox were called to give expert opinion evidence. Those opinions must be within their particular areas of expertise and the opinions must be based on their knowledge, training or experience. I am entitled to accept or reject any opinion evidence however before doing so I must consider the person’s qualifications, whether their opinion is based on a fact I accept, whether the opinion is in dispute and whether it fits with any other evidence that I have heard and accepted on that topic.
Election not to give evidence
Although the accused’s evidence was tendered from the previous trial, the accused elected not to give evidence at this trial. The accused was not bound to give evidence. The accused has the right to decline to give evidence. Because that is her legal right, I must not draw any inference adverse to her or the case the accused puts forward from the exercise of that right. There may be many reasons the accused did not give evidence, and I must not speculate on those reasons. I bear in mind that it is at all times, for the prosecution to prove its case beyond reasonable doubt.
Circumstantial evidence
In this case the prosecution relies upon circumstantial evidence. A guilty verdict cannot be returned unless the proven facts are such as to be inconsistent with any reasonable hypothesis other than guilt. Guilt must be the only rational inference the proven facts enable me to draw. The ultimate question must be decided having regard to all of the evidence, not in a piecemeal fashion.
Elements of the offence
The elements the prosecution must prove beyond a reasonable doubt are:
1.      The accused damaged property;
2.      The property is a building or motor vehicle;
3.      The accused caused the damage using fire or explosives;
4.      The accused intended to damage property or was recklessly indifferent as to whether his or her conduct would damage property.
It is not in dispute that the fire was deliberately lit by a person. What is in dispute is whether it is proved beyond reasonable doubt that it was the accused who lit the fire.
View
I have had the benefit of attending the shopping centre and observing the layout and the proximity of the relevant places: the post office, the toilets, and the back car park entrance. I take the view into account when assessing the evidence that was lead before this Court.
Background – matters not in dispute
There are a number of matters not in dispute which I find proven unless otherwise indicated. These matters were set out in a statement of Agreed Facts, tendered as Exhibit P24 and set out in full as follows:
STATEMENT OF AGREED FACTS
Fingerprints
1.   The following items were submitted at the South Australian Police Fingerprint Bureau for fingerprint examination:
a.14/A58392-14 (2L Coke Zero bottle)
b.14/A58392-17 (2L Pepsi bottle)
c.14/A58392-20 (2L Coke bottle)
d.14/A58392-23 (2L Coke bottle)
e.14/ A58392-26 (2L Pure water bottle)
f.14/A58392-29 (1.25L V8 juice bottle)
2.   No fingerprints suitable for comparison were located.
Chemical Analysis
3.   The following samples were delivered to Forensic Sciences of South Australia for analysis of ignitable liquid residues:
a.14/A58392-6 (remnants of plastic bottle)
b.14/A58392-7 (absorbent cloth)
c.14/A58392-16 (fluid sample from 2L Coke Zero bottle)
d.14/A58392-19 (fluid sample from 2L Pepsi bottle)
e.14/A58392-22 (fluid sample from Coke Bottle)
f.14/A58392-25 (fluid sample from Coke Bottle)
g.14/A58392-28 (fluid sample from 2L Pure water bottle)
h.14/A58392-19 (fluid sample from 1.25L V8 juice bottle)
i.14/A58392-49 (jeans)
j.14/A58392-19 (cardigan)
k.14/A58392-19 (singlet)
4.   Exhibits 14/A58392-40 (jeans), 14/A58392-43 (cardigan) and 14/A58392-44 (singlet) were each packaged within individual brown paper bags with each contained within metal tins. The air space was sampled from each of the metal tins while the packaged clothing remained within the tin and then examined for the presence of ignitable liquid residues.
5.   Each of the liquid samples were pale pink in colour which is the colour of unleaded petrol in Australia.
6.   The presence of components of petrol were identified in or on the following exhibits:
a.14/A58392-6 (remnants of plastic bottle)
b.14/A58392-7 (absorbent cloth)
c.14/A58392-16 (fluid sample from 2L Coke Zero bottle)
d.14/A58392-19 (fluid sample from 2L Pepsi bottle)
e.14/A58392-22 (fluid sample from 2L Coke bottle)
f.14/A58392-25 (fluid sample from 2L Coke bottle)
g.14/A58392-28 (fluid sample from 2L Pure water bottle)
h.14/A58392-31 (fluid sample from 1.25L V8 juice bottle)
i.14/A58392-40 (jeans)
7.   The presence of certain components of petrol on the cardigan and singlet could not be excluded.
8.   It is not possible to determine from chemical analysis whether the components of petrol located on any item of clothing was a result of the transfer of petrol in its liquid form or vapour form.
9.   Petrol evaporates overtime and can evaporate at different rates from different textiles or fabrics.
10.   Petrol is denser then, and therefore weighs, less than water. One litre (L) of water weighs one kilogram (kg), whereas one litre (L) of petrol weighs between 715 to 780 grams (g).
Fire Alarm
11.   Records from the South Australian Metropolitan Fire Service:
a.Record the automated alarm at Parafield Plaza Shopping Centre was activated at 5:21pm; and
b.That the first fire crew arrived at 5:31pm.
Height and Weight
12.   Medical notes from the Royal Adelaide Hospital record Shilane Quist as having a height of 163 cm and a weight of 63 kg on 23 December 2013.
Injuries
13.   Professor John Greenwood does not have the expertise to determine how the burns suffered by Shilane Quist were caused.
CCTV Enquires
14.   If he was recalled to give evidence, it is agreed that Detective Brevet Sergeant John Schuurmans’ further evidence would be as follows:
a.CCTV from the Australia Post Shop from 23 December 2013 was supplied to him on 6 March 2014 by Bruce Quist, the accused’s brother.
b.To his knowledge, there was only one camera located within the Post Office, although he did not check this at the time the footage was provided or after the fire itself.
The CCTV footage
There was a CCTV camera operating from inside the Australia Post shop.[1] Its field of vision incorporated most of the inside of the shop and relatively confined areas of the shopping centre floor beyond the glass door and windows of the shop. It does not capture the toilet area. The CCTV footage shows the accused walking away from the shop and out of vision. The footage then records, about six minutes later, an orange flash outside of the shop. The accused is then recorded coming into view, in a distressed state, proceeding to the front door of the shop. The accused suffered serious burns, caused by being close to the fire in the disabled toilet. The accused was the only person injured.
[1] Exhibit P18.
Previous civilian evidence
I have regard to agreed previous civilian witness evidence in the previous trial that was tendered in this trial.[2] This is a summary only. I have considered the entirety of the evidence.
Harpreet Kuar[3]
[2] Exhibits P7 & P8.
[3] Exhibit P8.
The witness was a cleaner at the Parafield Plaza at the time of the incident. Ms Kuar was tasked with cleaning the toilets. Ms Kuar did not notice anything out of the ordinary whilst they were cleaning the toilets the night before the incident. The witness stated that there was nothing out of the ordinary on the floor of the disabled toilets the day prior.
On the day of the fire, Ms Kuar and her husband opened the precinct at 7:00am and began cleaning the car park. They left the shopping centre between 8:00am and 8:30am. Whilst cleaning the toilets the morning of the incident, the witness did not notice anything out of the ordinary at the complex in the area of the toilets.
Alyssa Sobey
Ms Sobey was employed at the Australia Post shop at Parafield Plaza shopping Centre in December 2013. At the relevant time the witness was employed on a full-time basis and worked Monday to Saturday. Ms Sobey stated that the nail salon, which was next to the Australian Post shop at the time, was vacant and the Animal Welfare League generally shut at approximately 5:00pm. The witness noted the layout of the back room of Australia Post, which was not visible through the CCTV footage. Ms Sobey finished work at 5:10pm at the time of the alleged offending. The witness left the store and was with the accused and her mother at the front of the Post Office. This was consistent with the footage on file 3 of the CCTV footage. When Ms Sobey departed and headed towards Foodland, nothing was observed out of the ordinary.
Julie Magill
Ms Magill attended the shopping centre at approximately 5:10pm. The witness entered through the rear entrance near the Animal Welfare League. Ms Magill did not observe anything unusual. Ms Magill remained in Foodland for approximately 8-10 minutes, then observed commotion and heard screaming. The witness viewed smoke upon leaving Foodland and what Ms Magill described as a gassy substance coming out of the disabled toilets.
Briony Bunting
Ms Bunting attended Foodland at approximately 4:00pm or 5:00pm through the main entrance. The witness did not observe anything unusual. Ms Bunting observed the commotion that occurred as a result of the fire. Ms Bunting described hearing a female voice screaming ‘Someone help my daughter’ and observed a great deal of thick black smoke. The witness described the accused as smouldering with flames on her clothes and hair. Ms Bunting attended the post office and poured a bucket of water over the accused.
Joesph Sikora
Mr Sikora was a Drakes Foodland employee who assisted in putting out the fire. The witness was at the back of Foodland before being alerted to the fire. Mr Sikora smashed the glass to obtain the key to open the box to a fire extinguisher. Mr Sikora cut himself when the glass was smashed. The witnesses’ blood was found at the scene but was never tested. Mr Sikora noted the power point for the hand dryer was on fire and noticed a packet of matches inside the doorframe. The witness estimated that it took approximately five minutes to extinguish the fire.
Benjamin Huckstep
Mr Huckstep was the second Drakes Foodland employee who assisted in putting out the fire. The witness noticed that the industrial toilet roll was on fire as well as the other toilet roll. Mr Huckstep observed the fire scaling the right-hand side of the room.
Benjamin Stephens
Mr Stephens was the third Drakes Foodland Employee who assisted in putting out the fire. The witness arrived after the other two Drakes Foodland employees noticed that there was a fire.
Dr John Greenwood
Dr Greenwood was the Director of the Burns Unit and Consultant at the relevant time. Dr Greenwood provided an account of the injuries suffered by the accused.
Glen Shepherd
Mr Shepherd was a Detective Sergeant at the relevant time and was tasked to attend the Parafield Shopping Centre. Mr Shepherd gave evidence as to the crime scene and the various offices and MFS employees that attended.
Andrew Murphy
Brevet Sergeant Murphy had been a crime scene investigator since 2003. Brevet Sergeant Murphy had attended thousands of crime scenes and conducted hundreds of DNA swabs and received training in respect to DNA contamination. Brevet Sergeant Murphy attended Parafield Plaza with Sergeant Wynne.
Brevet Sergeant Murphy did not take any notes; however, he confirmed that if an item was handled; that is, in terms of collecting the item or taking a sample from the item, then it would have accordingly been marked with the Brevet Sergeant’s initials. Brevet Sergeant Murphy could not recall what if any assistance he provided to Sergeant Wynne during the investigation.
Andrew Chandler
Mr Chandler was the first MFS member to attend the scene. The witness stated that the automatic firearm alarm came through to the station at approximately 5:23pm. Mr Chandler indicated that the response was immediate. The witness arrived at the shopping precinct at 5:31pm.
Commander Jeffrey Ruxton
Commander Ruxton is a member of the MFS. Commander Ruxton had been a part of MFS for 37 years at the time of giving evidence. At the time, the witness was ranked Commander Central, South Area. At the relevant time of the incident, Commander Ruxton was Commander Manager in charge of the fire investigation section. Commander Ruxton’s duties and roles included to manage the section of the fire investigations and also be a part of the investigation team.
The witness attended the Parafield Plaza Shopping Centre on 23 December 2013 at approximately 7:00pm. Commander Ruxton attended alone and met with Sergeant Wynne at the scene. Commander Ruxton’s role and function at the scene was to assist SAPOL, specifically Sergeant Wynne. Commander Ruxton confirmed that one of the roles he performed was to take photographs as seen in Exhibit P2.
On entering the disabled toilet, the witness could smell some sort of petrochemical-type smell. Commander Ruxton observed that the ceiling fan cover had been displaced and was on the floor. The witness was involved in the removal of bottles from the ceiling cavity. The exhaust fan was removed to enable access to the roof space, which was where the bottles were discovered.
Bottle removal
According to the witness, the bottles were removed with a small step ladder and were removed one-by-one and they were handed to one of the police crime scene investigators. Commander Ruxton believed the bottles were handed to either Brevet Sergeant Murphy or Sergeant Wynne. The witness confirmed that they were the only persons present at the scene. Commander Ruxton advised that precautions were taken to prevent contamination of items in the form of wearing gloves. Commander Ruxton only wore one pair of gloves and did not change these gloves during the investigation. The witness stated that it was easier to take the photographs with the gloves on. The witness wore the same pair of gloves during the removal of bottles from the roof space and handled the bottom section of the bottles. Commander Ruxton was not aware of touching the lids of the bottles. The witness observed Brevet Sergeant Murphy and Sergeant Wynne completing DNA sampling of the lids. Both officers were wearing gloves. Commander Ruxton thought it was unusual that Brevet Sergeant Murphy was using multiple sets of gloves for each of the containers. The witness was not involved in the swabbing or sampling of the bottles.
Commander Ruxton stated that the void in the roof space was quite large, there was quite a lot of air space. There was one thermal detector located within the disabled toilet that triggered the automatic alarm.
Cross-examination
In cross-examination the witness was not able confirm where the ladder came from but believed it was brought to the toilet by an external individual. Commander Ruxton gave evidence that it was expected that Mr Chandler (who was first on the scene for MFS) would have verified that the fire was extinguished and would have been aware of interfering with evidence at the same time. If the fire was extinguished, then they were trained not to enter the area.
Commander Ruxton could not recall if he touched the top of the bottle lids. The witness was still on the ladder when the bottles were passed down to the investigator. Commander Ruxton was not directed by Sergeant Wynne as to how to handle the bottles. The witness confirmed that the bottles were handed down in a safe manner so they would not spill.
The witness was in possession of the camera throughout the entire investigation and did not pass it to Sergeant Wynne.
Commander Ruxton initially entered the shopping precinct without gloves, but did not touch any surfaces. The witness put gloves on attending the carpark to collect the camera kit.
Evidence at trial
There were four witnesses that gave evidence at this trial. They were Sergeant Jason Wynne, Dr Duncan Taylor, Detective John Schuurmans and Mr Simon Cox. The following is a summary of the evidence given by each witness. This is a summary only. I have considered the entirety of the evidence.
Sergeant Jason Wynne
Background & qualifications in relation to crime scene examination

At the time of the incident, Sergeant Wynne was a Brevet Sergeant and attached to the Forensic Response Section.[4] Sergeant Wynne is a qualified crime scene investigator. The witness completed two courses. One was called the crime visitation course and the second was the scene investigator course.[5] In both courses the witness learnt about crime scene processes including controlling the scene and collecting and recording evidence.[6] Sergeant Wynne gave evidence that any fire that involved injury or death was referred to the Forensic Response Section.[7]
[4]     T85.10.24.
[5]     T85.35.38.
[6]     T86.1.12.
[7]     T87.11.13.
The witness has a certificate IV in crime scene investigation and has completed a diploma and an advanced diploma in crime scene investigation.[8] Part of this training involved ensuring that crime scenes are preserved and not interfered with.[9] Sergeant Wynne has been an officer for 20 years and has previously appeared in this Court to give evidence.[10]
Crime scene practices
[8] T87.29.33.
[9] T91.7.9.
[10] T90.25.28.
Sergeant Wynne gave evidence that there are a number of ways to reduce the contamination of a crime scene.[11] Crime scene control is the first step. This involved limiting the amount of people that are allowed in and out of a crime scene. Depending on the crime scene itself, it may be appropriate to establish an outer cordon and inner cordon that restricts the flow of people.[12] There are also measures in place to reduce contamination, including using protective equipment such as gloves and a mask.[13] It is also important to ensure that officers are aware of the items that they are sampling, that they are not handling another item prior and possibly transferring and contaminating items and surfaces. Changing gloves when required is appropriate. If an investigator becomes aware of having touched a certain surface, it is general practice to change gloves.[14]
[11] T91.14.28.
[12] T91.16.20.
[13] T91.21.23.
[14] T91.23.28.
Gloves are used to avoid the transfer of DNA.[15] When taking a swab, it is appropriate practice to not place hands directly on either the swab itself or the item that is the subject of the swab. Thus, gloves are a physical barrier to prevent such contamination.[16] If an item is touched, it may transfer DNA inadvertently onto the gloves. The gloves operate as a barrier to prevent DNA contaminating a sample.[17]
Incident
[15] T91.32.37.
[16] T91.32.37.
[17] T92.2.6.
Sergeant Wynne attended the Parafield Plaza Shopping Centre at approximately 6:55pm on the day of the incident.[18] The witness was aware that there had been a fire within the premises sometime prior to attendance.[19] Sergeant Wynne was aware that the fire was said to have occurred sometime after 5:15pm.[20]
[18] T92.25.27.
[19] T92.28.30.
[20] T92.31.33.
If there is a fire scene that is to be attended by Forensic Response, then there is a memorandum of agreement with MFS that two fire investigators will attend, one from SAPOL and one from the MFS. A joint investigation will commence.[21]
[21] T93.2.8.
Sergeant Wynne was taken through the photographic exhibits.[22] The witness took photographs throughout the investigation. Following the photographs being taken, Sergeant Wynne commenced a physical examination, which included sampling.[23] The bottles that were located in the roof space were seized and swabs were taken from the lids. The two blood drops that were also identified in the photobook were swabbed and sampled as well as a number of areas inside the toilet block where the smell of petrol was present.[24] The smell of petrol in the various areas of the room included the drain area, under the exhaust fan and the melted bottle.[25] The melted plastic bottle had a fluid inside.[26]
[22] T95; Exhibit P2.
[23] T102.24.26.
[24] T102.24.31.
[25] T102.35.38.
[26] T103.
There were two methods of sampling that were employed. One was by swab and the other was by an absorbent cloth.[27] There was also a further six plastic bottles located in the roof space above the fan.[28] At some point Commander Ruxton removed the bottles from the roof cavity.[29] They used a ladder to reach the bottles. Sergeant Wynne instructed Commander Ruxton to remove the bottles in order to complete the sampling process. Sergeant Wynne instructed Commander Ruxton to only handle an area that was not the lid of the bottle.[30] The lid was a focus area for sampling to ascertain who tightened the cap on the bottles.[31] Commander Ruxton used gloves when removing the bottles.[32] The bottles were removed one by one from the roof.[33] Once a bottle was removed, it was taken by Commander Ruxton to another area within the shopping precinct and placed on the ground. Then Commander Ruxton would return and obtain the next bottle. Sergeant Wynne documented some details of the bottles. Once they were all retrieved, the investigators proceeded to the swabbing stage of the investigation.[34] This area was depicted in photograph 34 of Exhibit P2.[35]
Contamination
[27] T104.1.4.
[28] Exhibit P2.
[29] T104.8.11.
[30] T104.14.19.
[31] T104.21.24.
[32] T104.31.33.
[33] T104.34.36.
[34] T105.1.5.
[35] Exhibit P2.
As part of Sergeant Wynne’s role in processing the crime scene, a number of exhibits were seized. An ongoing exhibits log was maintained.[36]
[36] T106; Exhibit P6.
At approximately 8:50pm to 9:00pm, the bottles that were collected from the roof cavity were swabbed.[37] The swab that was used for DNA testing was a foam Popule swab, that was self-wetting and was prefilled with liquid inside of the tube. If the tube was broken, it then moistens the foam tip. A sample can then be taken from the area that is being targeted and placed into a container for storage and further analysis.[38] A swab was taken from each bottle that was collected.[39] It was solely the lid area where the swab was taken from.[40]
[37] T107.3.7.
[38] T107.13.18.
[39] T107.19.21.
[40] T107.22.23.
Precautions took place to prevent contamination, including ensuring the officers were wearing both gloves and a mask. It was Brevet Sergeant Murphy that took the swabs, whilst Sergeant Wynne observed the process.[41] Sergeant Wynne observed Brevet Sergeant Murphy wearing gloves and a mask. Each swab was contained within a sterile packet, it was opened, and the swab completed. It was then packaged into its tube prior to the next swab being taken.[42] Each swab had its own separate packaging. Sergeant Wynne observed Brevet Sergeant Murphy conduct each swab. The bottles were also intended to be examined for fingerprints at a later stage but the purpose of the swab at the scene was merely to assess the lids for DNA.[43]
[41] T107.28.38.
[42] T108.5.9.
[43] T108.23.38.
Prior to the process of swabbing, Sergeant Wynne gave a direction to Brevet Sergeant Murphy for the lids not to come into contact with any other item or surface when they were being removed from the roof cavity.[44] Each item was given its own exhibit number. Gloves were also changed between each swab. The witness observed Brevet Sergeant Murphy adopt this practice each time.[45] Sergeant Wynne gave evidence that it is general practice to wear two pairs of gloves, an inner and an outer pair. After the exhibits were taken, the outer glove was removed, and a new outer glove was replaced.[46]
[44] T109.25.27.
[45] T110.3.11.
[46] T110.12.17.
Various items that were lodged in the exhibit log are detailed in Exhibit P6. The items that were lodged are as follows:
·       PP1 was an ‘absorbent cloth’ that was used to sample for petrol at the site;
·       PP2 was a cotton swab, like an earbud that was used around the drain area;
·       PPS3 was another ‘absorbent cloth’ which was used in the same location, being the drain;
·       PP4 was the box of matches as depicted in Exhibit P2;
·       PP5 was an unburnt match which was on the floor near the exhaust fan cover;
·       PP6 was the remnants of PET bottle and was located on the floor on the east side of the toilet (this is the bottle where he smelt the scent of petrol);
·       PP7 is another ‘absorbent cloth’ that was used around where the melted bottle was located;
·       PP12 and PP14 were DNA swabs taken from inside the door handle;
·       PP14 was the first of the bottles from the roof cavity that was retrieved and swabbed;
oPP14.1 is the DNA swab of the bottle;
oPP14.2 is the fluid sample that was taken from the liquid contained with the bottle.
·       PP20 and PP21 was the blood swabs that were not subject to forensic analysis;
·       PP25 was the skin located on the glass window which again was not subject to forensic analysis;
·       PP28 were blue jeans of the accused which were preserved; and
·       PP29 to PP32 were further clothing items of the accused.
Process of moving exhibit items
Once the exhibits are packaged, they go into what is referred to as the ‘case management phase’ of the investigation. Each item is lodged onto the Police Property Management System.[47] Once all the exhibits were lodged in the exhibit log, they are transported to the Forensic Response Section office and placed into the secure exhibit room.[48] All exhibits that are collected are sealed and they are signed and dated so that the seal can remain, until it is subject to analysis and broken.[49]
Further precautions and details
[47] T118.25.38.
[48] T118.9.13.
[49] T119.7.13.
When Sergeant Wynne first arrived at the shopping centre, the area had been cordoned off by fire service tape.[50] The only officers that were present within the cordoned off area were Sergeant Wynne, Commander Ruxton and Brevet Sergeant Murphy when required to assist.[51] There were also other individuals present but they remained outside of the cordoned area.[52] An area was established called a ‘working area’ where the officers could change and hold equipment as required.[53] This area was around areas 12 and 13 as outlined in the floorplan, a short distance from the disabled toilet.[54]
Qualifications in relation to fire investigations
[50] T119.35.38.
[51] T120.4.7.
[52] T120.8.11.
[53] T121.7.12.
[54] Exhibit P1.
As part of Sergeant Wynne’s initial crime scene investigation training there was a fire cause investigation component.[55] There was a theory and practical component, which touched on structural fires, vehicle fires and bushfires.[56] The fire investigation component involved attending actual or real fire scenes.[57] In 2009 the witness completed a bushfire investigation course.[58] This course was run by the Country Fire Service. It included both theory and practical assessments. The theory was on the spread of wildfire and pattern indicators and the practical component involved simulated wildfire bushfires, which Sergeant Wynne would examine and determine the cause or the ignition area.[59] In 2011, Sergeant Wynne completed a fire investigation theory assessment. This involved specifics in respect of fire science, fire travel and spread, how to engage with other working parties such as a fire service; personal protective equipment, what equipment to wear at fire scenes, examining a structural fire, what fire patterns to assess and how to make an assessment of a cause and determination of the origin of a fire.[60] The practical part of the qualification was completed in 2013. This involved attendance as an observer and assistant at fire scenes. As Sergeant Wynne progressed through the practical component, further roles and responsibilities were conferred and the witness would take the lead from the fire investigator from the MFS.[61] The witness also studied both fire patterns and source of ignitions.[62] Sergeant Wynne noted that for a fire to burn or be sustained, there should be three factors: heat, oxygen, and a fuel source.[63]
[55] T131.5.12.
[56] T131.17.19.
[57] T132.28.30.
[58] T133.30.32.
[59] T133.34.38.
[60] T134.34.38; T135.1.4.
[61] T135.22.31.
[62] T136.31.36.
[63] T137.4.6.
Sergeant Wynne maintained up-to-date knowledge about fire investigations, including cause and origin.[64] As of December 2013 the witness had attended approximately 30 fire scenes.[65] At the time of giving evidence, the witness had attended approximately 80 fires, which included all types of fires.[66] Sergeant Wynne had been the primary investigator for about fifty percent of these fire investigations.[67] When the witness was a supervisor, it was common for other investigators to seek advice from the witness in relation to certain aspects of the fire investigation.[68]
Flash Fire
[64] T145.5.8.
[65] T146.1.3.
[66] T146.4.14.
[67] T149.11.21.
[68] T149.34.38.
A flash fire will occur when there is an ignitable liquid present that will produce a vapour, that vapour will diffuse in the air. If there is an ignition source introduced, such as a match, then there will be a rapid flame that will spread through that diffused air and vapour mixture.[69]
Backdraft effect
[69] T151.9.13.
Sergeant Wynne gave evidence that a ‘backdraft’ effect is an explosion event. Specifically, in a compartment or a room which is airtight, in that fire growth will be at the point where there is depleting oxygen in the compartment. As the oxygen is depleting, it will start burning down the fire but there will be highly energised particles still in the compartment. Thus, using the example of a window or a door when opened, there will be a sudden influx of oxygen, creating a backdraft event and an explosive effect.[70]
Fire cause
[70] T153.25.35.
There are many variables that may affect how quickly and how far a fire can spread.[71] When attending a fire investigation, the purpose is to determine what has occurred, if the cause of the fire can be identified and to identify an ignition source.[72] In the initial assessment and the examination recording phases, the general practice is to assess if there are any patterns that might indicate an area where the fire might have started.[73] The witness noted that damage can be so significant that it is not possible to determine a cause or origin of fire.[74]
Cause of fire
[71] T157.
[72] T158.4.6.
[73] T159.25.30.
[74] T160.7.9.
When Sergeant Wynne arrived at the scene, information was provided that there had been a fire in the disabled toilet and that a female had been injured and had been taken from the scene.[75] Information was conveyed that employees from Foodland extinguished the fire with fire extinguishers.[76] After receiving the initial brief information a forensic plan was implemented. The witness was shown photographs of the backpack (an examination of the backpack located occurred sometime after the initial examination).[77] The backpack was damaged which was likely by heat or flame.[78] There was blue powder across the floor which was a substance excreted from the fire extinguisher.[79] The toilet door sustained heat damage and there was soot present as well as blistering.[80] There were black markings above the doorframe as a consequence of the door being opened.[81] The markings on the top of the doorframe were likely caused by heat rather than flame itself.[82]
[75] T161.9.11.
[76] T161.18.
[77] T165.8.12.
[78] T166.30.32.
[79] T167.19.22.
[80] T167.35.38.
[81] T168. 13.17.
[82] T169.
Photograph 20 of Exhibit P2 depicted a matchbox. The witness was unable to recall if there were any unburnt matches within the matchbox.[83] The matchbox was not fully affected by fire.[84] Photograph 21 depicted the toilet roll and toilet paper where there was fire damage.[85] There was also another match found to the upper left of the drain.[86] Photographs 23 and 24 depicted a melted bottle or a plastic bottle in the corner next to the toilet.[87] Photographs 30 and 31 depicted a melted red bottle lid in the sink.[88]
[83] T170.37.38;171.1.
[84] T171.1.7.
[85] T171.8.19.
[86] Exhibit P2.
[87] T173.25.29.
[88] T174.
The toilet itself had soot staining similar to the door. There was a splash-type stain on the tiled wall.[89] This demonstrated that there was something burning near the toilet that was producing smoke and creating sooting. The markings on the wall could indicate that ‘something’s been splashed around’.[90]
[89] T175.9.12.
[90] T175.14.22.
Photographs 25 ad 26 depicted a bin against the wall. The bin sustained radiant heat damage, which melted the front of the bin. The toilet rolls sustained damage.[91] The fire did not start within the bin.[92] When assessing the cistern itself, the witness observed that there appeared to be a V pattern on that cistern caused by the flame below.[93] The V pattern indicated that there had been a flame in the area, which had burnt away the paint from that cistern.[94] The V shaped pattern started in the bottom right-hand corner and extended to approximately the centre of the top of the cistern.[95]
[91] T175.29.34; Exhibit P11.
[92] T177.1.3.
[93] T181.22.24.
[94] T181.30.33.
[95] T182.12.16.
Photographs 32 and 33 depicted the exhaust fan on the ceiling. The blades on the fan appeared to have been melted.[96] The material was likely made from plastic.[97] The exhaust fan would have been a ventilation point for the fire and the smoke.[98] The two bottles in the ceiling that were lying down sustained heat damage.[99] Following the removal of the exhaust fan cover, Sergeant Wynne did not make any further observations of the particular area.[100] The pattern underneath the exhaust fan cover itself was clean as it was protected by the cover.[101]The plastic from the exhaust fan could have melted from the bottle, which would then explain a clean mark on the ground next to the toilet.[102]
Workspace
[96] T183.
[97] T184.1.5.
[98] T184.27.31.
[99] T184.9.18.
[100] T189.4.6.
[101] T189.17.20.
[102] T190.9.13.
The cordoned off area that was used for the designated workspace is depicted in photograph 11 of Exhibit P2.[103] The location of the bottles is seen in Exhibit P4. Sergeant Wynne selected this specific work area as it had been cordoned off and was limiting access. There was also no other evidence that needed to be focused on in the immediate area.[104] The swabbing occurred in the same location as where the bottles were initially stored and then transferred into a bag at the equipment area.[105] The collection kit and other equipment including gloves and masks were also located in this area.[106]
[103] T185.
[104] T187.18.23.
[105] T187.28.30.
[106] T187.34.38.
One of the final processes was to clear the toilet floor to see if there were any other patterns or any other evidence that may be obscured by the debris to clean the toilet.[107]
Ignition source
[107] T188.10.15.
Sergeant Wynne believed the ignition source for this fire was the matches.[108] Specifically, the matches that are in the doorway and the unburnt match that was located near the drain.[109] The match is an ignition source that introduced the flame straightaway and there were accelerants present in the bathroom.[110] Sergeant Wynne excluded the hand dryer as being a possible ignition source given there was no actual damage sustained.[111] The witness excluded the fan as a potential ignition source.[112] Sergeant Wynne ruled out the possibility of the light switch in the toilet as being the source of the ignition.[113] The items in the roof space were not part of the actual cause determination. The cause was based on the evidence found on the melted bottle, the smell of the plastic, the swabs that were taken for further analysis and the matches themselves.[114] When assessing whether it was a deliberately lit fire, Sergeant Wynne took into account the liquid in the bottles, which were a reddish colour similar to petrol and had the smell of petrol.[115]
Characteristics of a flash fire
[108] T190.37.38.
[109] T191.1.4.
[110] T191.6.10.
[111] T191.16.19.
[112] T191.27.29.
[113] T177.22.25.
[114] T193.8.12.
[115] T193.15.17.

A flash fire does not always have an explosive effect or damage produced as a result of the effect. It is a flame that spreads rapidly through the diffused fuel, such as vapours or gas, that is mixed with air, which does not necessarily cause an explosion.[116] There are many variables and mixtures that affect a flash fire and how rapidly it develops.[117] The witness described a flash fire as a very fast moving flame, which would then disappear quite quickly. Once the flash fire is lit, it will ignite anything that is still able to burn and will continue to burn any items after the initial flash.[118]
Explosion damage
[116] T195.1.4.
[117] T195.
[118] T196.
In respect to blast damage, there are two types of explosions, namely detonation and deflagration. In relation to an explosion, heat, shock, noise and pressure is created. Depending on the type of explosion, will depend on the amount of damage that may be sustained. If it is a detonation where there is a crater or a blast, as it is instantaneous and quite a violent reaction, the items that are close by could be severely damaged, ripped apart and shattered. In a deflagration explosion, as the type of explosion is a burning effect, there will still be pressure, heat, and noise but the damage will not be as shattering as a detonation explosion. It will be an over-pressure and is capable of moving items. It will still produce a flame and smoke, but it will have as violent reaction as a detonation.
The type of space within which an explosion occurs is a relevant factor. Confinement is a factor on whether items will detonate or just burn. The witness gave an example in relation to a sparkler. If you were to take a number of sparklers off and just put those materials on the ground and set this alight, it will just burn. However, if you were to place those materials into a pipe, confine it within the pipe and then ignite it, as it is confined within that pipe, it will explode and detonate rather than deflagrate.[119]
Backdraft effect
[119] T199.1.7.
There is an explosive force when a backdraft fire effect occurs.[120] This is a deflagration explosion and would be on the lower scale of the explosion scale.[121] A backdraft effect occurs when the oxygen level in an airtight room is depleted.[122] The size of the fire required to deplete enough oxygen depends on a number of variables such as how much heat is being released, the fuel load that is available within the room and then the time of how long the fire has been burning to generate the energised material in the room and then finally the introduction of the oxygen.[123] The witness noted that time is also a significant factor in a backdraft fire. The fire has to develop to a point where it is producing enough energetic material in the room to suffocate the room of oxygen.[124] The greater the ventilation, the longer the time is required for the fire to advance to the state of smouldering or decay.[125] Given the fact that Sergeant Wynne did not observe any real explosive damage in the room as well as there being vapours in the room in the form of petrol, ultimately Sergeant Wynne concluded that it was less likely to be a backdraft effect.[126]
Accelerant
[120] T199.31.32.
[121] T199.35.36.
[122] T200.1.4.
[123] T201.6.10.
[124] T201.24.26.
[125] T201.27.29.
[126] T206; T207.
Sergeant Wynne gave evidence regarding the properties of petrol in terms of its flammability. The witness noted that petrol is quite flammable, its flash point is low.[127] Sergeant Wynne described it as quite a volatile substance.[128]
CCTV footage
[127] T202.16.20.
[128] T202.21.23.
The witness gave evidence that the flash of light that was seen in the CCTV footage could be consistent with a flash fire event.[129] The door would have to be opened at some point for the flash of light to be visible on the CCTV footage.[130]
Hypothesis of fire
[129] T202.34.38.
[130] T203.6.9.
Sergeant Wynne concluded by stating that, having regard to all relevant factors, the most probable hypothesis of the cause of the fire was that it was a deliberate fire by the ignition of some ignitable fuel, being petrol.[131]
Cross-examination
Petrol smell
[131] T208.
The witness confirmed that the bottles had a strong smell of petrol. The petrol smell was present inside the toilet block itself and was still present whilst the swabbing process was completed.[132]
Contamination
[132] T210.31.33.
The swabbing of the bottle tops occurred whilst the bottle tops were still intact on top of the bottles.[133] Thus, the bottles were not opened at the scene. The witness did not take a note of any of the bottles leaking petrol when they were stood up or laid down on the floor of the shopping centre.[134]
[133] T211.1.3.
[134] T211.16.19.
Sergeant Wynne described the contents of the crime scene manual that sets out procedures that should be adhered to by those working at a crime scene.[135] Sergeant Wynne was aware of the ever present risk of contamination given extensive past experience.[136] The witness was aware of the high obligation of documenting accurately the work conducted at a crime scene.[137] Sergeant Wynne double gloved when handling potential exhibits.[138] However, no notes of how many gloves were worn or changed during the investigation was recorded.[139] Sergeant Wynne’s general practice was to create a rubbish bag to place used gloves in. There was a rubbish bag in the area of the equipment.[140] The witness could not recall how many gloves were worn.[141] Once a division of labour was established, a record was completed from the start time to the end time. If there was something that was of concern, then it would be documented accordingly.[142]
[135] T212.1.4.
[136] T212.5.9.
[137] T212.10.14.
[138] T212.26.28.
[139] T212.29.38.
[140] T213.
[141] T213.32.33.
[142] T213.33.36.
Sergeant Wynne confirmed that Commander Ruxton and Brevet Sergeant Murphy were working together as part of the investigation at the scene.[143] Brevet Sergeant Murphy only performed the swabbing. The actual fire examination and the other sampling was conducted by Commander Ruxton.[144] Sergeant Wynne noted that they were not ‘in lockstep’ with each other throughout the entirety of the investigation at the scene. Sergeant Wynne accepted that a potential source of contamination can arise from the way an exhibit was handled within the crime scene.[145] Sergeant Wynne’s notes reflected that the sampling occurred, but the notes did reflect by whom or at what time. The movement of the exhibits collected was reflected in Sergeant Wynne’s exhibit list.[146] The witness did not take a note of the order in which any of the six bottles were removed from the ceiling space.[147] There was no note as to who swabbed the bottle lids.[148] Upon reviewing transcript of previous trials conducted in this matter, Sergeant Wynne accepted that he was in fact involved in sampling of the bottle lids.[149] In hindsight, the witness accepted that notes as to who removed the bottles would have been appropriate in the circumstances.[150]
[143] T214.1.3.
[144] T214.9.11.
[145] T214.29.32.
[146] T215.9.12.
[147] T215.27.30.
[148] T215.35.38.
[149] T218.
[150] T219.27.30.
Sergeant Wynne understood that the accused would have moved through the shopping centre from the location of the fire in the direction of the post office.[151] Notwithstanding this, Sergeant Wynne confirmed that the workstation area was still suitable. Sergeant Wynne did not see potential issues with the floor space being an area to work from for sampling. The witness stated that as long as the lid did not come into contact with the floor, the risk of contamination was minimised.[152] Sergeant Wynne did not hold any reservations in relation to the location of the work station near the melted skin that was found as that particular skin was stuck to a window and there was no disturbance to the skin.[153] Not every droplet of blood was documented on the floor within the shopping centre besides the two that were located in the corridor close to the work station.[154] If the investigation was conducted again, the witness would have adopted the same work station and practices in relation to the swabbing procedure.[155]
Exhibit D13 – photograph of sampling area
[151] T220.6.10.
[152] T221.23.28.
[153] T222.27.28.
[154] T223.1.8.
[155] T227.7.9.
The blue case depicted in Exhibit D13 was a collection case.[156] The paper bags that are seen in Exhibit D13 are the bags that contained the bottles that were removed from the roof space.[157] Each bottle was placed in a separate bag. The bottles were placed straight into the bag. The paper bags were stored in the large black case seen in Exhibit D13.[158] The phials that contained the swabs, were sitting on the floor in a plastic container. The container was on the tiled floor.[159] The purpose of the container was to protect the swab, so once the swab was taken, it was placed in the container and sealed to protect the swab. Therefore, there were no concerns regarding the container being in contact with the floor.[160] The witness did not record any notes in relation to where the lids for each of the phials that contained the swabs were placed once they were removed.[161]
[156] T227.
[157] T228.5.7.
[158] T228.21.26.
[159] T229.32.34.
[160] T230.8.10.
[161] T231.3.6.
Sergeant Wynne did not have any information as to the direction that any members of the ambulance service might have travelled in within the shopping centre either when they arrived or when they left.[162] The witness did not know if any medical treatment was provided to the accused at the scene.[163]
Clothing
[162] T232.19.22.
[163] T232.24.25.
Whilst Sergeant Wynne was at the scene, other police officers arrived and provided clothing that was said to have been worn by the accused. It was Detective Webber that delivered the clothing in a number of separate brown paper bags.[164] The following items were delivered: one brown paper bag containing blue jeans, one brown paper bag containing a black bra, one brown paper bag containing black undies, one brown paper bag containing a pink cardigan, one brown paper bag containing a red singlet.[165] These items were received in the car park of the shopping centre.[166] Sergeant Wynne did not record notes of where the clothing was received.[167] The clothing was then put into a fire tin. The purpose of the fire tin was to enable tests to be completed at a later time in respect of whether there were any vapours on the clothing.[168] Sergeant Wynne does not have any notes of when this occurred.[169] The items were placed straight into the tin and then sealed. The witness touched the outside of the brown paper bag when doing this. The witness confirmed that this did not take place in the toilet to reduce the risk of contamination.[170] Sergeant Wynne wore two pairs of gloves during the process of placing the brown paper bags in the tin.[171]
Commander Ruxton
[164] T242.1.9.
[165] T242.19.30.
[166] T242.32.34.
[167] T243.1.4.
[168] T243.8.11.
[169] T243.16.17.
[170] T244.
[171] T245.13.20.
Sergeant Wynne was not ‘in lockstep’ with Commander Ruxton during the investigation. They would consult each other on matters but they were not physically with each other for the whole investigation at the scene.[172] The photographs were taken by both Sergeant Wynne and Commander Ruxton and the same camera was used.[173] The camera was being handed back and forth between each other.[174] No notes were recorded of who took which photo.[175] Sergeant Wynne accepted that the camera was a vector for potential DNA contamination.[176]
Pen
[172] T256.
[173] T256.33.38.
[174] T257.3.6.
[175] T257.12.15.
[176] T258.26.30.
Sergeant Wynne utilised one multi coloured pen that was used throughout the investigation.[177] The witness accepted that the pen was a potential vector for contamination of DNA.[178]
Swabbing
[177] T258.
[178] T258.31.34.
The swab containers were labelled each time. It was Sergeant Wynne’s general practice to initial the outside label of the swab container.[179] The person that seals the bag will be the person who initials it.[180] Sergeant Wynne believed it would have been the person doing the swab and who handled the vial that initialled the swab container.[181] However, Sergeant Wynne had no notes of this. The lid of the vials was screwed onto the container. Then the lid would be unscrewed to take the sample.[182] Sergeant Wynne was involved in this process and assisted Brevet Sergeant Murphy.[183] Sergeant Wynne gave evidence that as the reporting officer, ‘I don't want to be the person that opens that swab’. However, the witness may have opened the container to the swabs.[184]
[179] T261.14.19.
[180] T261; T262.
[181] T262.21.25.
[182] T263.18.26.
[183] T264.4.6.
[184] T264.19.25.
The witness believed that Brevet Sergeant Murphy would complete the swab and sealed it into the container and labelled it.[185] In terms of Sergeant Wynne’s memory of the swabbing process, the witness was reliant on what was standard practise.[186] Sergeant Wynne confirmed that the match box was not swabbed for DNA.[187] Part of the officer’s training was to identify objects or surfaces that might be a possible source of evidence such as DNA and then to take samples from that particular area[188]
Protective equipment
[185] T265.29.35.
[186] T266.4.6.
[187] T267.7.11.
[188] T270.7.11.
Sergeant Wynne was wearing a face mask, gloves and fire boots.[189] The witness did not believe Brevet Sergeant Murphy was wearing over boots at the time.[190]
Movement of the accused
[189] T266.24.38;267.4.
[190] T267.5.6.
Sergeant Wynne accepted the possibility that there was movement by the accused within the shopping centre after the accused was burnt, albeit, it was not clear on exactly where that was.[191] There were particles of dirt or dust that might have come from the fire itself that was across the floor and surfaces within the shopping centre.[192]
Qualifications
[191] T267.23.26.
[192] T267.28.30.
Sergeant Wynne does not have any tertiary qualifications in chemistry or science apart from the advanced diploma through the Canberra Institute of Technology.[193] The witness completed this qualification in 2015 or 2016, which was two to three years after the alleged offending.[194] It was at the end of 2013 that Sergeant Wynne became authorised for the first time to conduct solo fire investigations.[195] The witness had conducted one fire investigation prior to this incident which was a house fire where the house was completely destroyed.[196]
[193] T372.1.8.
[194] T372.13.17.
[195] T372.20.23.
[196] T372.29.38.
The only other matter where the witness had given evidence in court in relation to fire cause investigations was in 2018.[197] In relation to the trial in 2018, there was no obvious indication of any accelerant being used. Instead, the cause was more likely due to a fuel load from inside the house.[198] Ultimately, Sergeant Wynne only gave evidence in respect of the area of where the fire was rather then how it started.[199]
[197] T374.
[198] T374.
[199] T374.27.33.
This is the first case in which the witness had been asked as an expert to proffer an opinion about the mechanism by which a fire might have started.[200]
Hypothesis in relation to fire
[200] T374.34.38; T375.1.
The appropriate scientific method, in terms of a fire investigation, is to define a problem, in this case, it is the fire itself, develop a hypothesis, gather information to test that hypothesis and then adjust, confirm or negate that hypothesis.[201] When completing a hypothesis, there are a number of different theories that can be tested, one of the hypothesis was that an accelerant was used to start the fire. Another hypothesis could be where did the fire start and how did it start. The observation of the matches contributed to the hypothesis that the fire was started by match.[202] Sergeant Wynne gave evidence that a hypothesis could be formed based on observations at the scene coupled with further analysis. This was an ongoing or working hypothesis based on observations.[203] As part of the hypothesis developed, the match was either part of the initial ignition or that the match may have been dropped after ignition.[204] The witness did not consider the fact that the matchbox was possibly there for another reason other than being the ignition source of the fire.[205]
Matchbox damage
[201] T376.9.15.
[202] T377.1.9.
[203] T378.11.12.
[204] T386.11.13.
[205] T387.7.
The damage to the matchbox was deceiving in the photographs due to the fire extinguisher powder. The damage was contained to the fan, the toilet rolls dispenser and the bin. Once the room was cleared, the floor was relatively clear of any damage.[206] The unburnt match that was found near the exhaust fan cover was in relatively good condition.[207]
Backdraft effect
[206] T385.2.10.
[207] T385.14.15.
In terms of the pre-requisites for a backdraft to occur, Sergeant Wynne accepted that the first pre-requisite is a compartment or a room.[208] The second pre-requisite for a backdraft is an airtight room where a fire is still burning. There is no ventilation requirement for the fire to start. The backdraft effect requires an airtight room where oxygen is being depleted from the fire.[209] It was suggested that a room or a compartment does not have to be airtight in order for there to be a backdraft event. The witness stated that there is a requirement that there be an airtight or near airtight compartment for the backdraft event to occur. Sergeant Wynne explained that upon reviewing the relevant studies and materials on the subject, there will always be natural ventilation. This ventilation could be caused from a door crack or a window crack.[210] When Sergeant Wynne gave evidence in respect of ‘air tight’, this does not refer to no air whatsoever.[211] The witnesses’ understanding was that any fire, if it consumes the oxygen in a near airtight environment, once there is an influx of oxygen it may create an explosive event.[212] The witness accepted that putting aside whether it was a ventilation controlled fire or not, in the lead-up to a backdraft event, the fire will create a hot gas layer.[213] This occurs as the fire is searching for its highest point in the room and it will start moving towards the ceiling, thus creating the hot gas layer.[214]
Ventilation controlled fire
[208] T389.10.13.
[209] T389.17.22.
[210] T389.35.38; T390.1.4.
[211] T390.5.7.
[212] T392.26.29.
[213] T393.20.21.
[214] T393.20.29.
Sergeant Wynne did not give evidence as to ventilation controlled fires at the previous trial. However, the witness was able to give evidence on this topic at this trial. Sergeant Wynne stated that if a room was fully involved in the fire, there could be ventilation being controlled by an opening. Sergeant Wynne’s knowledge was still limited on this topic.[215]
Deflagration and detonation
[215] T390.25.33.
Sergeant Wynne gave evidence in respect of the differences between deflagration and detonation. Deflagration takes place at a velocity lower than the speed of sound. Contrastingly, detonation is faster than the speed of sound. Both are explosive events and will produce light, heat and a shock wave.[216] In terms of a deflagrating explosion in a compartment, the pressure increases, until it finds the weakest point, which may be a window, door opening or roof.[217] The increasingly hot air and the increasing pressure searches for an exit from the compartment.[218]
[216] T395.32.35.
[217] T397.9.13.
[218] T397.16.19.
In the event that there is a backdraft in the room, Sergeant Wynne accepted that a deflagration explosion would be capable for the door to be blown out.[219] Another way in which the backdraft event could occur is if the door was opened, letting oxygen in and then the deflagration event occurred.[220] If the door was opened and the oxygen was introduced and mixed, there is no barrier and the deflagration event will consume the room.[221] In terms of sound, detonation is a crack that you would expect to hear when you have a detonation.[222] The deflagration sound is not an explosion sound. Instead, it would be a movement-type sound of the fire or the actual event occurring through the air.[223]
[219] T398.1.
[220] T398.6.10.
[221] T398.6.10.
[222] T402.7.9.
[223] T402.9.13.

In terms of the sound of the deflagrating explosion itself, there may be no more than a whoosh venting outside the door once it is opened. However, it depends on the size of the event.[224] Sergeant Wynne accepted it was difficult to say with any precision regarding the size of the event in this matter.[225]
Type of fire
[224] T404.24.25.
[225] T404.28.
In cross-examination Sergeant Wynne opined that the fire was a flash fire. Sergeant Wynne’s knowledge was limited in respect of backdraft fires and could not exclude this ideal as a possibility in this case.[226] The witness sought further peer review studies due to a lack of knowledge that was identified at the previous trial.[227] Sergeant Wynne was unable to undertake calculations to determine what is known as a ventilation factor.[228] Due to being unable to perform this type of calculation, it was difficult for the Sergeant Wynne to form an opinion regarding whether there was a ventilation controlled fire.[229]
[226] T406.23.35.
[227] T408.
[228] T408.33.37.
[229] T409.14.19.
A key determining factor that led the witness to determine that it was a flash fire was the absence of any explosive damage within the compartment.[230] The other factors in favour of the fire being a flash fire included: that there was petrol within the room, the potential for the vapours (petrol) to mix with oxygen and there was an ignition source that can cause these vapours to ignite. Factored into this opinion was the observation that the toilet roll had burnt.[231] With a flash fire, one of the characteristics is that the fire will ignite other combustible items in the room such as the toilet roll dispenser.[232] Sergeant Wynne accepted that the damage within the disabled toilet was generally at a higher level,[233] that is, peeling and blistering of the upper level of the room.
CCTV footage
[230] T412.12.14.
[231] T412.19.29.
[232] T425.1.6.
[233] T426.16.20.
Sergeant Wynne gave evidence that the footage was not of great assistance. It was very quick and was at an angle that did not provide a line of sight.[234] At the last trial the witness was not prepared to give evidence that the flash of light might relate to or what it might or might not be consistent with.[235] Sergeant Wynne cautiously expressed that it could be a fire, or it could be something else.[236]
Smoke explosion
[234] T416.8.10.
[235] T416.4.8.
[236] T416.24.27.
Sergeant Wynne’s understanding which was limited, confirmed that a smoke explosion commences very similar to that of the backdraft scenario, but a smoke explosion does not necessarily need an introduction of oxygen. It is the energised materials in the room which ignite and cause an explosion.[237]
[237] T412.3.8.
Dr Duncan Taylor
Background & qualifications
Dr Taylor is employed by the Forensic Science Centre of South Australia (FSCSA) and was employed as the Chief Scientist of Forensic Statistics at the time.[238] Dr Taylor worked at the State Forensic Centre since 2005.[239] I have regard to Dr Taylor’s curriculum vitae when assessing the relevant qualifications.[240] Dr Taylor has two PhD’s, one in molecular biology and the other in statistics.[241]
[238] T281.8.
[239] T281.10.14.
[240] Exhibit P15.
[241] T281.23.29.
Both Dr Taylor’s report and the table of results from Ms Windram were tendered as part of this trial. I have regard to both exhibits when assessing the evidence before this Court.[242]
[242] Exhibit P16; Exhibit P17.
Dr Taylor had given expert evidence in respect of DNA analysis in over a hundred trials in both the Supreme and District Courts of South Australia.[243]
[243] T283.12.18.
Dr Taylor provided one report in relation to this particular matter. There was also another report that was prepared by other scientists that Dr Taylor had regard to in preparation of their report.[244]
[244] T283.2.5.
Dr Taylor gave evidence that DNA was a substance present in most cells of the human body. DNA is located within cells. [245] Some sources of DNA such as biological fluids are richer than others. If you have a sample that has a very rich source of DNA, it increases the chances that scientists will be able to generate a DNA profile from that sample. If there is a large sample of a very DNA-rich source, then it would be easier to generate a DNA profile. Contrastingly, when assessing trace DNA samples, the DNA profile may have such low levels of DNA that a DNA profile cannot be generated.[246]
DNA transfer
[245] T283.23.27.
[246] T284.13.23.
There are a number of factors that will dictate whether or not DNA is left on an item.[247] The factors that will effect this included: how long that item was touched for, how much pressure was applied or whether there was any friction involved in the touching, and the property of the surface of the object. Once DNA has been deposited onto an item, whether or not it persists on that item depends on the conditions that the item was kept within, such as exposure to water, moisture or heat that can break down DNA. Whether or not DNA will be detected will depend on the sampling device used, whether the sample area contained remaining DNA and whether a DNA profile can be generated from that sample.
[247] T284.31.33.
Dr Taylor gave evidence that there is a concept in forensic science known as shedder status. That is, studies have shown that certain people tend to be more prone to shedding their DNA or leaving their DNA on items which they have touched as opposed to other individuals.[248] If increased pressure or friction is applied, then more DNA may be deposited onto an object, and in particular if that object has a rough surface.[249]
Bottle cap DNA transfer
[248] T286.11.15.
[249] T286.21.27.
A bottle cap contains features that may increase the likelihood of DNA being deposited. A key feature includes the rough surface of the ridges. Likewise, typically when removing or tightening a bottle cap, there is pressure or friction involved. These two aspects can increase the amount of DNA that might be deposited onto a bottle cap. This has a practical effect that there is an increased possibility that a DNA profile may be able to be generated and sampled.[250] Dr Taylor noted that moisture and heat will tend to break down DNA.[251]
Primary transfer
[250] T286.36.38; T287.1.7.
[251] T287.14.17.
Primary transfer or direct transfer is transfer of DNA from a person to an object because they have come into direct contact with that object.[252] An example is holding a pen, where there would be DNA left from the direct transfer of touching the pen.
Secondary transfer
[252] T288.1.3.
Secondary transfer is when DNA is deposited on an item from an individual, not because they have touched it directly, but due to their DNA being transferred through an intermediatory object. An example of this is if a person shakes a person’s hand outside of the courtroom, some of their DNA may have transferred onto the persons hands. If that person handles, for instance, a pen and if that pen was tested, the pen might detect DNA from both persons involved in the scenario.[253]
FSCSA
[253] T288.13.25.
Dr Taylor confirmed that there were a number of swabs received by the FSCSA in relation to this matter. When the samples were sent to FSCSA, they are either in a sealed bag or envelope that is sealed until it is opened for analysis.[254] A swab is submitted straight to the laboratory technicians.[255]
[254] T292.2.5.
[255] T292.11.12.
There are a number of processes that are conducted to generate a DNA profile. The first would be DNA extraction, where DNA is released from any material that is present on the swab. The second would be quantification, which determines how much DNA has been obtained. The third is polymerase chain reaction (PCR) which targets specific areas of interest in forensic profiling. The final stage is called capillary electrophoresis. This is where the areas that have been amplified are run out on an instrument and appear as bumps on a graph, and that is what is known as a DNA profile. Each of those particular stages have various processes and procedures and controls to ensure that the sample integrity is maintained throughout the process.[256]
[256] T292.20.33.
During the extraction phase gloves are changed between handling of swabs.[257] Dr Taylor then detailed the steps taken to avoid contamination of the contents of the swab.[258]Dr Taylor confirmed that scientists are trained not to touch the swab head with their gloves. The swab head will be minimally or not be touched at all, and either forceps or scissors are used to remove that swab head from its original holder into the extraction tube.[259] If a result was received where there had been some form of contamination, there would be an investigation into how that contamination had occurred but ultimately the contamination would be reported.[260]
[257] T293.19.21.
[258] T294.19.30.
[259] T294.36.38.
[260] T297.23.25.
When DNA profiles are obtained, the first step is to assess the profiles to ensure their suitability for analysis. The scientists determine a reasonable number of individuals that may have contributed DNA to a sample. An assessment is made as to whether if it is a single source evidence sample, or whether it could be a sample contributed to by multiple people (mixed profile). Once the number of contributors has been ascertained, the profile is analysed in a computerised system which detangles mixed DNA profiles into individual profiles. The reference DNA profiles are the compared to the evidence DNA profile using a computerised system to yield a statistical weighting.[261]
DNA sampling – DNA samples extracted from two swabs
[261] T299.12.30.
The first item from which a DNA profile could be extracted was a swab of the 2 litre Pepsi bottle lid.[262] The second item from which a DNA profile could be extracted was a swab of a 2 litre water bottle lid.[263] The DNA profile description concludes that there is a Mixed DNA profile of three contributors for the 2 litre Pepsi bottle and two contributors for the 2 litre water bottle.[264] There was insufficient DNA for profiling in relation to the other bottle lids that were swabbed.
Hypothesis
[262] T301.10.12
[263] T302.10.12.
[264] T302.18.19.
When a DNA profile is analysed through the STRmix computerised system, two possibilities are considered. One is that the person being compared is a contributor of DNA to that sample and the other is that the person that is being compared is not a contributor of DNA in that sample and any similarities between the reference and the evidence sample would therefore have to be by chance. When considering the two competing hypotheses, a calculation is expressed in the form of a likelihood ratio, which is the statistical weighting in favour of either hypothesis.
In relation to the 2 litre Pepsi bottle swab, FSCSA received a mixed DNA profile that has originated from three contributors. Consideration is given to two different hypotheses when comparing the reference sample to the evidentiary sample. Firstly, the three contributors of DNA are the accused and the two other unknown individuals (hypothesis 1). The alternate hypothesis considered was whether the DNA profile originated from three unknown people and the accused is not one of the contributors of DNA (hypothesis 2). In this case a likelihood ratio of 19 billion was in favour of the first hypothesis.[265] This means that there is extremely strong support for the first hypothesis, that is, the accused is one of the three contributors to the DNA profile.[266] In relation to the 2 litre Pepsi bottle, further analysis was conducted and statistical weighting of 4.8 billion was found in favour of, again, hypothesis 1, being that the accused’s DNA profile was a contributor to the mixed DNA sample.[267]
[265] T303.7.34.
[266] T304.4.7.
[267] T305.28.30.
The STRmix analysis of these profiles provides further information regarding the DNA profiles during the analysis. For this particular sample (2 litre Pepsi Bottle), the three contributors are broken down into percentages of 82%, 13% and 6% as the three contributors to the mixed DNA profile.[268] The accused’s reference profile most closely aligned with 82%.[269]
[268] T306.24.29.
[269] T306.32.33.
The next item that was analysed was a swab of a 2 litre water bottle. The DNA profile description was a mixed DNA profile of two contributors.[270] The two hypotheses or interpretations detailed in Ms Windram's report illustrated a statistical weighting of 19 billion in favour of hypotheses 1.[271] Upon re-analysis, the statistical weighting was 1.3 billion again in favour of hypothesis 1.[272] For this particular profile, there were two contributors broken into percentages of 94% and 6%.[273] The DNA profile of the accused most closely align with the 94% contributor in respect to this DNA profile.[274]
[270] T308.4.5.
[271] T308.9.12.
[272] T308.20.22.
[273] T308.31.32.
[274] T308.35.
Dr Taylor explained that the reason for the re-analysis and different results was as a result of new and improved version of STRmix being available by 2019, after the first trial and before this trial.
Dr Taylor noted that it is not always the case that if an individual does come into contact with an item that that DNA profile will be revealed as a contributor.
Cross-examination
FSCSA assume that the exhibits that are received have been handled appropriately and correctly by police.[275] If an individual is wearing gloves then that may minimise the chance of contamination.[276] Dr Taylor accepted that the presence of DNA does not provide any information as to how DNA was deposited on an item.[277]
Aerosol transfer
[275] T313.13.15.
[276] T314.1.2.
[277] T315.30.32.
Aerosol transfer occurs when DNA has been deposited on an item through no direct contact. Dr Taylor gave the example that all persons tend to shed skin cells and aspirate small saliva droplets and these can settle on items and on surfaces in quantities that may be detected.[278] Dr Taylor accepted that it is possible that, at any given time, there could be small amounts of cells that contain DNA floating in the air.[279] Dr Taylor noted that a human sheds millions of cells per day.[280]
Forensic procedures and contamination
[278] T317.5.11.
[279] T317.12.14.
[280] T317.25.27.
Dr Taylor gave evidence regarding quality assurance testing results. Dr Taylor noted that DNA from persons who did not work at FSCSA were found on various locations within the building.[281] The laboratory technicians taking the samples would wear masks, hair nets and booties.[282] There would be procedures employed regarding the use of any equipment that was in proximity to items that are being examined.[283] Dr Taylor accepted that if an individual either gloved or ungloved then made contact with another individuals DNA and then uses their pen, that person may have deposited that person’s DNA onto their pen.[284] It is possible to have DNA present on gloves, then transfer that DNA to a pen that is being used.[285] The witness confirmed that any tool that is used in the process of an examination is a potential vector for contamination, which includes a camera.[286]
[281] T321.19.22.
[282] T322.1.19.
[283] T323.21.28.
[284] T324.7.11.
[285] T324.22.23.
[286] T324.32.33.
It was put to the witness that if it was assumed that there was clothing that was being worn by the accused, when the accused suffered significant burns, it may be expected that as a result of that event those clothes or at least some of the clothes the accused was wearing at that time would be a rich source of DNA. Dr Taylor was not aware of any particular study that would address this topic, but from a commonsense view: ‘if you are badly burnt and your skin is weeping as it does when you are badly burnt, then you might transfer quite a lot of DNA through that biological fluid to something you were wearing’. Therefore, it could be a rich source of DNA.[287] Dr Taylor gave evidence that ideally there should be minimal movements of exhibits at a crime scene. For example, an item of clothing that was removed from the scene and subsequently returned is suboptimal.[288]
[287] T326.1.4.
[288] T326.25.38; T327.1.9.
Dr Taylor accepted that it was also suboptimal to place the exhibits (bottles) and conduct sampling on the floor.[289] It would help to minimise any potential contamination risk if there was a clean barrier between the item and wherever it was placed.[290] If the swabs are to be taken at the scene, then it should occur some distance from the area where it was suggested that the suspect or the victim has been burned or might have walked through after being burnt.[291] The best place to sample the bottles in question would be a location that was completely clean and separate to the location where the bottles were retrieved from.[292]
[289] T327.
[290] T328.6.8.
[291] T329.1.
[292] T329.2.6.
Dr Taylor accepted that it was possible that there could be skin cells or other biological material of the accused that could be deposited on the floor of the shopping centre.[293] It was possible that in the course of police moving in the area where the swabbing occurred, DNA from the accused could be re-circulated through the air.[294] Dr Taylor accepted it was possible some DNA might make contact with or land on a particular exhibit or more than one exhibit in that general area.[295]In terms of the state of the floor which bottles were placed, Dr Taylor accepted that that was far from ideal in terms of a surface for the bottles to be placed, if DNA swabbing was to be undertaken.[296]
[293] T329.
[294] T330.9.11.
[295] T330.16.18.
[296] T331.12.16.
The witness accepted that if a person wore the same pair of gloves the whole time and handled the bottles, it would be possible for DNA to be deposited on the lid of a bottle if the person came into contact with the lid of that bottle with their gloves.[297] The witness accepted that if a bottle was taken from the ceiling space and passed to one or more other persons who received the bottle, that could also lead to potential contamination.[298] Dr Taylor stated that the force with which a particular lid might have been touched, the duration of time that the lid might have been touched, what part of the gloves or gloves made contact with the lid, could then result in the accused’s DNA being a contributor to the mixed DNA profile of the bottle lids.[299]
Re-examination
[297] T337.33.38.
[298] T338.1.7.
[299] T338.25.38.; T339.14.
Dr Taylor stated that with aerosol transfer you would probably expect to see multiple DNA across items. Dr Taylor also gave evidence about a study, the effect of which was to suggest that the less time you spend in an area, the less opportunity there is for DNA shedding. The witness identified that the unknown in this case was that the subject had suffered burns and what impact this might have on shedding.
Detective Brevet Sergeant John Schuurmans
Background
Detective Brevet Sergeant John Schuurmans has been a police officer for 32 years.[300] Detective Schuurmans was stationed at the Barossa Criminal Investigation Branch. At the time of the offending, Detective Schuurmans was stationed at Elizabeth Criminal Investigation Branch.[301]
Investigation
[300] T348.7.9.
[301] T348.13.14.
Detective Schuurmans attended the Parafield Plaza Shopping Centre and arrived just after 5:30pm.[302] On arrival Detective Schuurmans spoke with Detective Sergeant Matthews.[303] The witness then attended the RAH to make inquiries of the accused.[304] Detective Schuurmans was with Detective Webber at the time. Initially the witness spoke with one of the staff members at the RAH that was dealing with the accused and then spoke very briefly to the accused and collected her clothing, along with some personal items.[305] The clothing that was collected consisted of a red top, a pink cardigan, a black bra, black underpants, blue jeans, one white thong and an Apple iPhone in a pink cover.[306] All of the items were seized . The clothing was provided to Sergeant Wynne and the mobile phone and thong were lodged with the Elizabeth property section.[307] Detective Schuurmans seized the CCTV footage as part of the investigation.
Cross-examination
[302] T348.33.38.
[303] T349.11.12.
[304] T349.15.19.
[305] T349.28.31.
[306] T349.34.36.
[307] T350.2.5.

Defence counsel addressed the issue of the CCTV footage regarding the accused movements prior to the fire. The accused attended the post office, placed the bag on the counter, leaving it unattended and was depicted on CCTV. Defence counsel submitted that this behaviour was inconsistent with a person that was aware of where every camera was.
Good character evidence
Good character evidence was received in the form of the transcripts of the character witnesses that were called at the previous trial.[444] Defence counsel submitted that good character combined with the absence of motive raises itself a doubt of the accused’s guilt aside from the other difficulties in the prosecution case which are not sufficient to prove the accused’s involvement.
Ms Sobey
[444] Exhibit D28.
Defence counsel highlighted that Ms Sobey did not smell anything out of the ordinary within the shop. This was significant against the background of the prosecution case being that the bottles were with the accused in the shop for upwards of half an hour, including the accused leaving the backpack unattended on the front counter for up to five minutes. Ms Sobey gave evidence that it was common for the accused to have a folder of documents as well as carry a bag or a backpack. It was common for the accused to visit her mother to receive washing and ironing. Thus, there was nothing unusual as far as Ms Sobey’s evidence was concerned regarding the accused attendance at the Post Office.
Detective Schuurmans
Detective Schuurmans was provided at the hospital a plastic bag containing all of the accused’s clothes. Detective Schuurmans then removed, wearing gloves, one item of clothing, placed it into a brown paper bag with gloves on, folded the brown paper bag over and sealed it. Detective Schuurmans candidly stated that the changing of gloves did not occur during this process as it was for residue testing so ‘there was no need to change them’.
Ultimately, defence counsel submitted that, having regard to the real possibility of contamination or there being an innocent explanation for the DNA evidence said to implicate the accused, together with the correct conclusion that the fire was a backdraft or smoke explosion, and assessing the evidence as a whole, the prosecution has not excluded as a reasonable possibility any hypothesis consistent with innocence.
Circumstantial evidence
It is well established that where a case is premised entirely on circumstantial evidence, the trier of fact is required to consider the whole of the evidence in assessing whether the prosecution have proven the charges beyond reasonable doubt. As stated by Dawson J in Shepherd v The Queen:[445]
As I have said, the prosecution bears the burden of proving all the elements of the crime beyond reasonable doubt. That means that the essential ingredients of each element must be so proved. It does not mean that every fact — every piece of evidence — relied upon to prove an element by inference must itself be proved beyond reasonable doubt. Intent, for example, is, save for statutory exceptions, an element of every crime. It is something which, apart from admissions, must be proved by inference. But the jury may quite properly draw the necessary inference having regard to the whole of the evidence, whether or not each individual piece of evidence relied upon is proved beyond reasonable doubt, provided they reach their conclusion upon the criminal standard of proof. Indeed, the probative force of a mass of evidence may be cumulative, making it pointless to consider the degree of probability of each item of evidence separately.
[445] (1990) 170 CLR 573 at 579-580.
I remind myself of the remarks of Gummow, Hayne and Crennan JJ in R v Hillier:[446]
… It has often been said that a jury cannot be satisfied beyond reasonable doubt on circumstantial evidence unless no other explanation than guilt is reasonably compatible with the circumstances. It is of critical importance to recognise, however, that in considering a circumstantial case, all of the circumstances established by the evidence are to be considered and weighed in deciding whether there is an inference consistent with innocence reasonably open on the evidence. [footnotes omitted]
[446] (2007) 228 CLR 618 at [46] per Gummow, Hayne and Crennan JJ.
In a circumstantial case, there will be evidence of matters which, looked at in isolation from other evidence, would yield an inference compatible with the innocence of the accused. A circumstantial case is not to be considered in piecemeal fashion. It is the combined strength of all of the circumstances that needs to be assessed. Lest there be any uncertainty, this is the approach I have adopted in this case.
Primary topics of controversy
Whilst I must assess the evidence as a whole, as I am required to, there arose two primary areas of controversy at trial. First, the potential contamination of the DNA evidence said to implicate the accused which was located on the two lids from bottles located in the roof of the disabled toilet. Second, the specific cause of the fire, namely whether it was a flash fire or a ventilation controlled (backdraft or smoke explosion) fire. I will assess each of these issues whilst having particular regard to the expert evidence that was lead at trial as well as all other evidence before the Court.
The prosecution case is that on 23 December 2013 the accused took seven soft drink bottles filled with petrol into the disabled toilet at the Parafield Plaza shopping centre, placed six bottles through the ceiling fan space into the ceiling space, splashed petrol from the seventh bottle around the room and struck a match igniting the petrol. The prosecution case was that the accused suffered serious burns to her chest, back, arms, knees, and feet as a result of the ‘explosion’ of the petrol inside the room.
Ultimately, the prosecution submitted that I must consider whether the accused was so unfortunate as to find herself in the wrong place at the wrong time after somebody else had lit the fire in the disabled toilets and then as a result of her burns, distributed DNA across the floor of the shopping centre which was in turn then mixed up and landed on only two of the bottles. A similar submission was made in relation to the possibility that there was some alternate innocent explanation that caused the accused’s DNA to be transferred to the bottle lids.
Contamination
I deal first with the presence of a DNA profile on two of the bottle lids relied upon by the prosecution as a piece of circumstantial evidence implicating the accused as the arsonist. As the prosecutor correctly observed during her closing address ‘the accused’s DNA on the lids of the bottle and the petrol is, of course, a fundamental aspect of the prosecution case’.[447] The accused submits that it cannot be excluded that the implicatory DNA profiles are present as a consequence of contamination and/or innocent deposition.
[447] T689.13-15.
I have regard to the agreed facts which confirm that fluid samples were taken from each of the six bottles located at the scene. All of the bottles were found to contain petrol.
DNA matching the accused was located on the lids of two of the bottles retrieved from the roof space, being the Pepsi bottle and on the water bottle. Insufficient DNA for analysis was located on the Coke Zero, Coca Cola and V8 juice bottles that were laying down in close proximity to the floor. Another Coca Cola bottle lid appears to have been swabbed (according to the exhibits list), but no DNA results were before the Court in relation to this particular swab.
Commander Ruxton’s handling of the bottles requires consideration.
Commander Ruxton wore the same single pair of gloves for the duration of his ‘time at the scene’. Those gloves were put on before Commander Ruxton entered the disabled toilet. In evidence, Commander Ruxton stated:
·       That he believed the door to the toilet was open, but could not be sure;
·       That the bottles were taken out carefully;
·       That he was not aware of touching the lids of the bottles and can’t recall whether he touched them or not;
·       That he and Sergeant Wynne shared the same camera when taking photographs at the scene;
·       That he saw Brevet Sergeant Murphy changing gloves.[448]
[448] T935.
Sergeant Wynne stated in his evidence:
· That upon reflection, both he and Brevet Sergeant Murphy were likely involved in the swabbing process;
· That whilst Sergeant Wynne was changing gloves between handling potential exhibits, Brevet Sergeant Murphy was not.
Both Commander Ruxton and Sergeant Wynne could not categorically account for the handling of these exhibits, nor exclude the real possibility of material contamination of the exhibits. Brevet Sergeant Murphy has no specific recollection as to his handling of the exhibits.
There are inconsistences between Sergeant Wynne, Commander Ruxton and Brevet Sergeant Murphy regarding the precautions taken to prevent contamination and the sampling process. They are summarised as follows:
·       Sergeant Wynne states he instructed Commander Ruxton to only handle an area that was not the lid of the bottle. Contrastingly, Commander Ruxton stated that he was not directed by Sergeant Wynne to handle the bottles a certain way.
·       Sergeant Wynne gave evidence that Commander Ruxton came down the ladder each time, walked the bottles up the corridor and placed each individual bottle down in the sampling area before returning to the toilet to retrieve the next bottle. Conversely, Commander Ruxton gave evidence that each bottle was passed down to either Sergeant Wynne or Brevet Sergeant Murphy and he remained on the ladder.
·       Commander Ruxton stated that he took all of the photographs at the scene. Conversely, Sergeant Wynne stated that he and Commander Ruxton would each have taken photographs and handed the camera back and forth throughout the course of the investigation (Ruxton without changing gloves).
·       Commander Ruxton observed the swabbing process. However, Sergeant Wynne stated he was not in lockstep with Commander Ruxton during the investigation. They would consult each other on matters but they were not physically with each other for the whole investigation at the scene.
·       Sergeant Wynne was only involved in the swabbing process in terms of taking notes. However, under Cross-examination, Sergeant Wynne accepted that he may have assisted Murphy in this process and held the vial that the swab was put in or even taking the yellow lid off the vial and holding it and then screwing it back on.
These inconsistencies are to be considered in circumstances where Brevet Sergeant Murphy gave evidence in general terms that he had little independent recollection of this particular investigation and did not make any notes of his involvement in the investigation.
There is uncertainty and a lack of note taking in relation to how the vials used for taking the swabs and the bottle lids were handled and by whom. There are inconsistences in the evidence of Commander Ruxton, Brevet Sergeant Murphy, and Sergeant Wynne as to who handled the bottles, how the bottles were handled, how they were transported to the processing area and how the swabbing was performed. The evidence leaves open as a very real possibility (to say the least) that Commander Ruxton’s hands and hence single pair of gloves came into contact with surfaces of the disabled toilet area such as the door or door handle, where the accused’s DNA may have been as a consequence of her accessing the toilet, before he then handled the lids of the bottles. That being a reasonable possibility, I am unable to exclude the hypothesis that the accused’s DNA came to be on the bottle lids by way of secondary or tertiary transfer. Put another way, the interaction Commander Ruxton had with the scene and his handling of exhibits gives rise to the distinct possibility of contamination.
Contamination via aerosol transfer
The location which Sergeant Wynne selected to test the bottles also exposes the real possibility of contamination. The bottle lids were staged in a location on the ground in close proximity to the toilet area where the accused was badly burnt and subsequently moved through on her way back to the post office. The lids were swabbed in this area. Dr Taylor confirmed that this examination station may have been inadequate or not ideal in terms of preventing contamination. As much was accepted in the prosecution closing address.
In respect of aerosol transfer, Dr Taylor was not able to exclude that someone who is severely burnt might shed their DNA at a greater rate than someone who is not, albeit that he was not aware of any studies regarding whether shedding increases for burnt victims. I have regard to the limitations expressed on this aspect of the evidence of Dr Taylor.
Dr Taylor gave evidence on the topic of aerosol transfer. A summary appears in these Reasons. I have assessed the evidence on aerosol transfer in the context of the circumstantial evidence as a whole. Having undertaken that wholistic analysis, I am unable to exclude as a reasonable possibility that there may have been innocent deposition of the accused’s biological material onto the relevant bottle lids via aerosol transfer. The location of the exhibit processing area in close proximity to the toilet, the placement of the bottles onto the floor in that area, the evidence of Sergeant Wynne that Commander Ruxton walked each of the individual bottles to the processing area, one at a time, thereby permitting differential deposition of airborne biological material across the individual exhibits, the evidence that the accused was badly burnt in the immediate vicinity shortly prior, together with the evidence of Dr Taylor means that aerosol transfer is a reasonable possibility.
Notwithstanding that it is highly suspicious that the accused’s DNA was a likely contributor to the lids of two bottles that were originally located in the ceiling of the disabled toilet, given the practices adopted by the forensic investigators, inconsistences on their evidence, particularly as to the handling of exhibits, lack of contemporaneous notes, the unsatisfactory location of the exhibit station which was set up nearby to the disabled toilet and the accused’s movement in close proximity to the disabled toilet and having regard to all of the evidence, I am unable to exclude innocent deposition as a reasonably possible explanation for the DNA evidence. Contamination of the exhibits is a reasonable alternative hypothesis in the particular circumstances of this case. In reaching this conclusion, I am satisfied that the evidence and submissions of defence are more than mere conjecture.[449]
[449] R v Baden-Clay (2016) 258 CLR 308 [47].
Cause of the fire
When assessing the cause of the fire, I have regard to the evidence of Sergeant Wynne and Mr Cox, together with the entirety of the evidence.
Mr Cox’s qualifications and experience outweighs that of Sergeant Wynne’s. Mr Cox was an impressive witness. The prosecution expert, Sergeant Wynne, could not exclude the possibility of a backdraft. Sergeant Wynne did not possess the same level of knowledge in relation to backdraft or ventilation controlled fires. Sergeant Wynne was not able to complete calculations in respect of ventilation controlled fires.
Whilst Mr Cox made a point of criticising Sergeant Wynne for not excluding every possible hypothesis of an ignition source, both Sergeant Wynne and Mr Cox were in agreeance that the electrical appliances within the room could be excluded as possible ignition sources.
Both Sergeant Wynne and Mr Cox were in agreeance that the damage to the walls, the hair dryer and the light switch were the result of the heat from the hot gas layer that was radiating either from the fire, or as Mr Cox concluded from a backdraft effect. Both experts agreed the fire, whatever its form, was deliberately lit.
Mr Cox gave evidence that the injuries sustained by the accused were more consistent with a backdraft effect or smoke explosion, rather than a flash fire. If a flash fire were to occur, the height of the flame would have been much lower, about 10-20cm from the ground. Mr Cox also noted that the damage to the door frame of the disabled toilet and the soot that was present on the door frame was consistent with a backdraft effect occurring. Thus, the accused’s injuries and damage within the disabled toilet are consistent with a backdraft effect occurring, as opposed to a flash fire. In making this observation, of course, Mr Cox is not a medical practitioner. However, it is the cause of the injury (i.e. the nature of the fire) that is the focus of the evidence, not the medical detail of the injury, which is a burn or burns.
Further, the orange flash captured on the CCTV supports the hypothesis that the accused opened the door on a pre-existing ventilation controlled or oxygen depleted fire and suffered burns as a result of a fireball caused by a backdraft event.
This hypothesis is also consistent with the civilian witnesses at the shopping centre not observing anything unusual prior to what became the obvious fire event causing the injuries to the accused. For practical purposes, the closed door of the toilet concealed the ventilation controlled fire prior to the door being opened, leading to the backdraft, which caused the injuries to the accused.
Evidence of bags
The prosecution submitted that the Court should draw an inference that the bags carried by the accused visible on the CCTV footage contained the bottles filled with petrol. Again, I consider this submission in light of the entirety of the evidence. The CCTV footage is not clear enough to ascertain the contents of the bags. The witness, Ms Sobey, stated that the accused would typically arrive at the Australia Post shop carrying a bag as part of her regular attendances at her mother’s shop. The actions of the accused, first, placing the bags on the service counter at the Australia Post shop then, second, leaving the bags in that location unattended is inconsistent with the Crown’s theory regarding the contents of the bags. Whilst the appearance of the backpack may have changed when the mother of the accused appears in the CCTV holding what seems to be the backpack after the fire, there is a degree of uncertainty about this.
Defence were critical of the lacuna in the evidence as to the backpack itself. The backpack was never tendered, there was no evidence about its physical characteristics, material from which it was made, its construction and the potential impact of the fire upon it.
In considering this strand of the circumstantial evidence as part of an assessment of all of the evidence, these issues need to be borne in mind.
Good character evidence
The accused called three witnesses at a previous trial, Alison Rundle, Sharon Rathbone and Joanne Newman, to give evidence as to her good character and reputation. This evidence was tendered by consent as Exhibit D28.
Alison Randle has known the accused for ’30 plus’ years through community netball and she said the accused is well-liked, trustworthy and that she has a reputation for honesty.
Sharon Rathbone has known the accused for 30 years through netball and work. She said the accused has a reputation for being an honest person and helps people a lot.
Joanne Newman has known the accused for approximately 10 years. Ms Newman spoke of the accused’s reputation as a very honest, very loyal person. The accused was described as having an ‘upstanding reputation’.
The evidence of the accused’s good character is relevant for the following purposes:
First, when assessing the credibility or truthfulness of the accused’s evidence. A person of good character is generally considered to be less likely to lie or to give a false account of themselves when giving evidence, and as such, this is a consideration when deciding whether to accept the accused’s evidence.
Second, it is evidence that can be used in determining the likelihood that the accused committed the offence. This is because it is generally considered that a person of good character is less likely to commit a criminal offence and, in this way, evidence of good character should be taken into account when determining whether the prosecution has proved its case beyond reasonable doubt.

Naturally, a person of good character is capable of committing a criminal offence. This is to be borne in mind.
Conclusion
Having regard to all of the evidence, I find the fire was deliberately lit. I accept the evidence of Mr Cox that the accused was burnt by a ventilation controlled fire that was already burning in the disabled toilet. I find that the accused was burnt when she opened the door of the toilet by reason of a backdraft event.
It remains necessary to consider the prosecution’s alternative contention that I can be satisfied that the accused was the arsonist nonetheless on the basis that the accused set the fire burning, with the resultant backdraft event.
In support of this hypothesis, the prosecution relied heavily on the DNA evidence, linking the accused to the bottles containing accelerant. As I have previously said, the prosecutor’s submission was that: ‘the accused’s DNA on the lids and the petrol is, of course, a fundamental aspect of the prosecution case’.[450]
[450] T689.13.15.
Having identified the importance of this particular piece of circumstantial evidence, I make it clear that it is not an indispensable link in the chain of reasoning to establish an element of the offence.[451] It is a piece of evidence to be considered with all of the evidence in deciding whether the offence has been proved beyond reasonable doubt.
[451] Shepherd v The Queen (1990) 170 CLR 573.
Again, having regard to all of the evidence, in the particular circumstances of this case, I cannot exclude as a reasonable possibility that the presence of DNA profiles on the lids of the bottles is attributable to innocent deposition through one of the mechanisms discussed in these Reasons for Verdict.
On the evidence of Sergeant Wynne, Brevet Sergeant Murphy, Commander Ruxton and Dr Taylor, there is a reasonable possibility that the DNA samples consistent with that of the accused were deposited via means other than the accused touching the lids of the two bottles.
Having regard to all of the evidence, I accept the evidence of Mr Cox as to his primary opinion as to the nature of the relevant fire. That is, that the fire which injured the accused was a backdraft event, which was burning before the accused opened the door of the toilet. In her actions opening the door, the accused sustained serious burn injuries. Having made these findings, the question then becomes has the prosecution, having regard to all of the evidence, excluded a reasonable possibility consistent with the innocence of the accused?
Discussion – evidence of accused
In assessing whether the evidence of the accused is reasonably possibly true, I take into account the submissions of the prosecution and defence, together with all of the evidence.
There is nothing unusual or nefarious about the accused not immediately attending to the stated purpose of visiting the shopping centre, to purchase food. A careful reading of the evidence reveals that part of her reason for attending was to see if a parcel her husband was expecting had arrived, not that she was to collect a parcel that had already arrived.
However, the evidence from the accused regarding what bag she was carrying whilst walking in between the post office and her car is unclear at best and incorrect at worst. The accused described the bag as being an everyday shopping bag, and adopted the (leading) description given by counsel of a ‘Woolies’ or ‘Coles’ bag or ‘something like that’.[452]
[452] Defence counsel from the previous trial was not counsel at this trial.
The CCTV footage from the Australia Post shop (Exhibit P18) is far from clear, but neither of the bags being carried appear to match that description.
Further, as was emphasised by the prosecution, the accused’s description of the door to the toilet being ajar or ‘sticking out a little bit’ prior to her being burnt is at odds with the evidence of Mr Cox concerning a ventilation controlled fire burning within. For reasons above, I accept the evidence of Mr Cox on this topic and have found that a backdraft incident caused the injuries to the accused, casting additional doubt on the accuracy of the evidence of the accused.
Further, it is apparent the accused’s recollection generally about events of the day in question is unreliable. She was unable to recall what time she attended the shopping centre and has very little, if any, specific memory in the aftermath of being burnt.
The concession from the accused stating that she was “not sure what my memory is” as to her ability to recall events is telling.
In the circumstances, I have reservations about the reliability of the accused’s account. The discrepancies I have mentioned relate to important topics and adversely impact upon her reliability. The evidence of the accused was infected with unreliability.
The cross-examination of the accused at this trial was relatively brief (3½ pages of transcript) and was tendered as part of Exhibit P7. I did not have the opportunity to assess the accused’s demeanour and make my assessment based on the face of the record.
In assessing the credibility of the accused, I have regard to the entirety of her evidence in conjunction with the entirety of the evidence presented at trial, including the evidence of good character adduced on her behalf. The findings I have made above regarding the accused’s reliability are quite separate from an assessment of her credibility. I do not accept the failings in her reliability reflect adversely on her credibility.
During the course of cross examination, the accused’s evidence remained intact. There were no proven lies, nor did the answers given expose anything that would cause me to doubt the truthfulness of her denials as to the suggestion that she was the arsonist.
Whilst I have found that the evidence of the accused is infected with unreliability, the same does not apply to an assessment of her credibility. Noting that I did not have the opportunity to observe the demeanour of the accused whilst giving evidence and assessing her evidence on the face of the record, there is no reason for me to reject the accused’s denials of lighting the fire as not being reasonably possibly true.
Of course, the infirmities of the accused’s evidence in terms of its reliability adds nothing to the prosecution case and is not a makeweight. The burden remains fixed on the prosecution to prove its case beyond reasonable doubt.
During the prosecution address, reference was made to the evidence of Ms Magill, a member of the public who attended at the shopping centre on the day in question. Ms Magill gave evidence at a previous trial. That evidence was tendered in the current trial. The prosecutor referred to the evidence of Ms Magill that, in the immediate aftermath of the accused being burnt, being doused in water and then being attended to by paramedics for her injuries, the accused asked ‘where is my bag’. Whilst passing reference was made by the prosecutor on this topic during the closing address and similarly passing reference was made to the topic of consciousness of guilt, this submission was not further developed. As I understand the final position, the Crown did not press reliance upon this aspect of the evidence as reflecting a consciousness of guilt. Given the state of the evidence before me and the fact that this submission was not further developed, I do not consider that this evidence is capable of evidencing a consciousness of guilt on the part of the accused.[453]
[453] Edwards v The Queen (1993) 178 CLR 193.
Findings
1.      At some time prior to 5.15 pm on 23 December 2013, a fire was deliberately lit in the disabled toilet inside (the toilet) near one of the entrances to the Parafield Plaza Shopping Centre on Salisbury Highway (the shopping centre).
2.      The fire was started with the assistance of an accelerant, namely petrol.
3.      Six bottles containing petrol were placed in the roof cavity of the disabled toilet by the arsonist.
4.      Before the fire, the accused was present at the shopping centre in the nearby Australia Post shop operated by her mother at the relevant time.
5.      The accused attended at the Australia Post shop carrying a black backpack and another black bag.
6.      The accused left the two bags on the front counter of the Australia Post shop before removing them to the back room of the outlet.
7.      After the last customer had been served at the Australia Post shop the accused left the Australia Post shop with both bags, heading in the general direction of the toilet through the shopping centre.
8.      Approximately 6 minutes later, an orange flash is observed on CCTV footage, noting that the CCTV footage does not cover the area of the toilet.
9.      Approximately 30 seconds after the flash, the accused returns to the Australia Post shop.
10.    Upon her return to the Australia Post shop, the accused had suffered burn injuries.
11.    Approximately 12 seconds later, the mother of the accused returns to the Australia Post shop with what appears to be a backpack.
12.    Fire cause investigators seized six bottles containing petrol from the roof cavity of the toilet.
13.    DNA testing revealed the presence of a DNA profile on two of the bottle lids for which there was extremely strong support for the proposition that the accused was a contributor.
14.    Chemical analysis is unable to determine whether the presence of components of petrol on the clothing of the accused was caused by transfer of petrol in vapour or liquid form.
15.    The fire incident responsible for the orange flash observed on the CCTV was caused by a backdraft incident.
16.    The injuries to the accused were caused when she opened the door to the toilet, thereby precipitating the backdraft incident.
17.    At the time the accused opened the door to the toilet, a deliberately lit fire had already been started in the toilet.
These findings are made having regard to the entirety of the evidence.
I am not satisfied, having regard to all of the evidence as to the primary contention of the prosecution, namely that the accused was injured as a consequence of being present inside the toilet at the time that she ignited petrol causing a flash fire.
Having made that finding, I am required to consider whether on all of the evidence, I am satisfied beyond reasonable doubt of the alternative hypothesis advanced by the prosecution, namely that the accused deliberately set a fire in the toilet at an earlier time and was subsequently injured as a consequence of opening the door, thereby precipitating the backdraft incident.
In this regard, the ultimate question remains whether the prosecution has proved beyond reasonable doubt that the accused was the arsonist, in particular whether the totality of the evidence excludes any reasonable hypothesis consistent with her innocence.
I will not fully repeat defence counsel’s submissions, which are set out above. In essence, it was submitted on behalf of the accused that having regard to all of the evidence, there was insufficient evidence to prove the prosecution case; that various of the inferences I was asked to draw could not be drawn given the deficiencies in that evidence (one such example being the real possibility of contamination of the DNA evidence). It was submitted that the absence of motive, together with the good character of the accused undermines the inferences sought to be drawn by the prosecution. Of course, I accept that the prosecution does not have to prove a motive.
Part of this global assessment necessarily includes the finding that, having regard to the whole of the evidence, I cannot exclude the denials of the accused as not being reasonably possibly true.
I have carefully reviewed the totality of the evidence and the submissions of the prosecution and defence, to consider whether I am able to exclude all reasonable hypothesis consistent with innocence and whether the matters urged upon me by defence counsel rest upon more than mere conjecture.[454]
[454] R v Baden-Clay (2016) 258 CLR 308 [47].
While I am able to make some findings and draw the inferences I have set out above, having regard to all of the evidence, I am not satisfied that the prosecution has proved beyond reasonable doubt that the accused lit the fire.
I find the accused not guilty.