R v Nguyen - [2010] SASCFC 23

SUPREME COURT OF SOUTH AUSTRALIA
(Court of Criminal Appeal: Criminal)
R v NGUYEN
[2010] SASCFC 23
Judgment of The Court of Criminal Appeal
(The Honourable Justice Vanstone, The Honourable Justice White and The Honourable Justice Kelly)
18 August 2010
CRIMINAL LAW - PARTICULAR OFFENCES - DRUG OFFENCES - POSSESSION - WHAT CONSTITUTES
CRIMINAL LAW - APPEAL AND NEW TRIAL - PARTICULAR GROUNDS OF APPEAL - MISDIRECTION AND NON-DIRECTION - PARTICULAR CASES - WHERE APPEAL DISMISSED
Criminal law - appeal against conviction - appellant convicted by jury of two counts of trafficking in a controlled drug - where trafficable quantities of drugs found in appellant's house - where circumstantial evidence suggested appellant dealing in drugs - where appellant alleged drugs belonged to another who was in the house at the time of their finding - whether trial Judge's directions inadequate.
Held (per Vanstone and Kelly JJ, White J dissenting): appeal dismissed.
(per Vanstone and Kelly JJ): trial Judge's directions on the issue of possession adequate - trial Judge did not invite the jury to infer possession from agreement with another to sell - agreement to sell was one realistic scenario for the jury's consideration.
(per White J dissenting): although not necessary to direct that joint possession can occur when acting in concert, trial Judge's directions did not explain the concept of joint possession at all - trial Judge conflated notions of joint possession with joint intention to sell - link to intention to sell drugs may have confused jury.

CRIMINAL LAW - APPEAL AND NEW TRIAL - VERDICT UNREASONABLE OR INSUPPORTABLE HAVING REGARD TO EVIDENCE - APPEAL DISMISSED
Whether jury verdicts unreasonable.
Held (per Vanstone and Kelly JJ, White J not deciding): permission to appeal refused - verdict of jury not unreasonable - jury entitled to conclude on the entirety of the evidence that appellant was selling drugs from her house either on her own account or with another.

STATUTES - SUBORDINATE LEGISLATION - VALIDITY
Whether regulations prescribing trafficable quantity invalid for unreasonableness.
Held (per White J, Vanstone and Kelly JJ agreeing): regulations prescribing trafficable quantity not invalid - stringent test to be applied - no lack of proportionality to enabling legislation demonstrated - regulations not unreasonable.
Controlled Substances Act 1984 (SA) s 4, s 32 and s 63; Controlled Substances (Serious Drug Offences) Amendment Act 2005 (SA) s 4 and s 14; Controlled Substances (Controlled Drugs, Precursors and Cannabis) Amendment Act 2008 (SA) s 4(3); Controlled Substances (General) Regulations 2000 (SA) reg 6, Sch 1 and Sch 2; Narcotic and Psychotropic Drugs Act 1934 (SA) s 5; Controlled Substances (Prohibited Substances) Regulations 2000 (SA) reg 6 and Sch 2; Controlled Substances (Poisons) Regulations 1996 (SA) reg 31K and Sch KA, referred to.
Dib & Dib v The Queen (1991) 52 A Crim R 64; State of South Australia v Tanner (1988) 166 CLR 161; Williams v Melbourne Corporation (1933) 49 CLR 142; Minister for Resources v Dover Fisheries (1993) 116 ALR 54; Mixnam's Properties Ltd v Chertsey UDC [1964] 1 QB 214; R v Turner (1980) 24 SASR 217, discussed.
R v GNN (2000) 78 SASR 293; R v Zampogna (2003) 85 SASR 56; R v Granger [2004] SASC 156; De Silva v Minister for Immigration and Multicultural Affairs (1998) 89 FCR 502; Guo v Minister for Immigration and Citizenship (2009) 176 FCR 83; R v Mason (2000) 77 SASR 105; R v Frangos (1979) 21 SASR 331; Lai v The Queen (1990) WAR 151; He Kaw Teh v The Queen (1985) 157 CLR 523; R v Moubarak (2002) 219 LSJS 276; R v Davis (1990) 50 A Crim R 55; Moors v Burke (1919) 26 CLR 265; Borrillo v Bartlett [1966] SASR 286; R v Wan (2003) 140 A Crim R 513, considered.

WORDS AND PHRASES CONSIDERED/DEFINED
"possession", "joint possession", "acting in concert", "validity of regulations", "disproportionate to the purposes of the enabling legislation", "trafficable quantity"

R v NGUYEN
[2010] SASCFC 23
Court of Criminal Appeal: Vanstone, White and Kelly JJ

VANSTONE and KELLY JJ: This is an appeal against the conviction of the appellant by verdict of a jury of two counts of trafficking in a controlled drug contrary to s 32(3) of the Controlled Substances Act 1984 (SA) (“CSA”).
Several grounds are advanced. It is said that the verdict of the jury is unreasonable and cannot be supported having regard to the evidence; then, that the trial Judge erred by failing to give adequate directions with respect to the concept of possession and finally that the trial Judge erred in the directions he gave the jury on the operation of the presumption in s 32(5) of the CSA, because the regulation prescribing the trafficable quantity was invalid.
Background
Before dealing with these grounds it is convenient to summarise the relevant facts.
On the evening of 28 July 2008 police officers went to a house occupied by the appellant and her child at 61 Galway Street, Kilburn. At the time there were two people present in the house, namely the appellant and a man called Cabral. Cabral was searched and allowed to leave. The house was then searched. In the lounge room underneath a couch police located one small heart shaped ‘Betty Boop’ tin, a brown medicine bottle and a Winfield Blue cigarette packet. The tin contained heroin, the brown bottle contained methylamphetamine and the Winfield cigarette packet contained $1140.
Elsewhere in the home police located and seized a total of seven mobile telephones, only two of which appeared to be operational. In addition to the cash found in the Winfield cigarette packet, police found a further $1280 in the appellant’s handbag in the kitchen and $6510 in a bum bag locked in a red tin located in the main bedroom of the house. The appellant admitted that the cash in her handbag and in the red tin was her money. She denied that the cash found in the Winfield cigarette packet was hers. Most of the cash located was in $50 or $100 denominations. The prosecution presented evidence in the form of bank records which established that there were no large withdrawals from the appellant’s account during the relevant period such as to explain the large sums of money in her house.
The heroin inside the Betty Boop tin was in 12 individual balls packaged in plastic. That heroin was the subject of the first charge against the appellant. The total weight of the substance containing heroin was 2.17 grams, 0.43 grams (approximately 20 per cent) of which was pure heroin.
The methylamphetamine inside the small brown bottle was in 11 small re‑sealable plastic bags. That methylamphetamine was the subject of the second charge against the appellant. The total weight of the substance containing methylamphetamine was 3.83 grams, 1.36 grams (approximately 35 per cent) of which was pure methylamphetamine.
In an interview with the police the appellant acknowledged a number of important matters. She told the police that the house belonged to her and no other adult lived there. The appellant acknowledged that she knew the man Cabral, but said he was not living at her house and that he had arrived at her house shortly before the police arrived. She acknowledged that the car in the driveway, in which some empty re‑sealable plastic bags were found, belonged to her. She claimed that Cabral and a friend of his drove her car from time to time, although on the night the police attended she said she drove herself home alone. She said she had arrived at the property about 10 minutes before the police arrived. The appellant acknowledged owning a number of items located in the house which were important on the prosecution case. Those items included the brown methadone bottle in which the methylamphetamine was found and the Betty Boop container in which the balls of heroin were found. She acknowledged that she had a history of heroin use, that she knew how heroin was packaged and that she knew of some water balloons found in her kitchen. She admitted smoking Winfield Blue cigarettes.
At the trial expert evidence was led to establish the value of both the heroin and methylamphetamine and the quantities in which it is usually sold. There was some circumstantial evidence to connect the appellant to the packaging of both the heroin and methylamphetamine. There was expert evidence that street deals of heroin are commonly packaged in pieces of plastic shopping bags twisted and then tied or melted. Balls of heroin are then often placed inside a small water balloon because balloons are durable and protect the heroin and can be swallowed. A number of packets of water balloons were located in the appellant’s kitchen. The appellant admitted they were hers. The balls of heroin found in the appellant’s house had the appearance of street deals of heroin wrapped in plastic without having been placed in balloons.
The methylamphetamine was packaged in small re‑sealable bags. Some of the bags had Minnie Mouse sticky tape around them. The Minnie Mouse sticky tape was connected to the appellant in that, inside the red tin that the appellant admitted was her cash tin, there was, in amongst the $50 notes, one note with a piece of Minnie Mouse sticky tape attached to it. On the prosecution case the sticky tape on that money matched the sticky tape found on the bags containing methylamphetamine within the brown bottle. On one of the re‑sealable plastic bags inside the brown bottle containing the methylamphetamine was DNA which matched the profile of Cabral.
The appellant did not give or call any evidence at trial. The sole issue at trial therefore became whether the prosecution proved possession. If possession was proved, then by operation of the presumption in s 32(5) CSA the charges would be proved.
The presence of Cabral in the appellant’s house at the time of the arrival of the police was an important factor in the trial. The defence case was that in light of the fact that Cabral was present at the time when the police arrived and the fact that his DNA was found on one of the small re-sealable plastic bags containing methylamphetamine, found within the brown bottle hidden under the couch, the jury could not exclude beyond reasonable doubt that it was Cabral who was in sole possession of the drugs. It was common ground that Cabral was not living at the appellant’s premises, however the appellant admitted in her interview with police that she was going out with Cabral, that he and a friend of his, Michael, had been at her house often, that they in effect shared everything and that she would not have minded Cabral going through her things.
There were therefore two scenarios which the jury would need to exclude beyond reasonable doubt before convicting the appellant. The first was that Cabral put the drugs under the couch without the knowledge of the appellant. The second was that Cabral put the drugs under the couch with the appellant’s knowledge and acquiescence, but that she had nothing to do with them. On the other hand, the following scenarios if found beyond reasonable doubt could have led the jury to convict the appellant. The first was that Cabral put the drugs under the couch with both the knowledge and acquiescence of the appellant, and the appellant thereafter intended to assert custody and control, so that she was in sole possession of them. The other possibility, which in our view really flows from this, was that the appellant and Cabral were in joint possession of the drugs, as one or other of them put the drugs there with the knowledge and acquiescence of the other, as they were both selling the drugs. On that scenario, it did not matter which of either the appellant or Cabral, was actually going to do the selling.
Directions as to Possession
In the light of this, the trial Judge’s directions to the jury needed to convey that before they could convict the appellant they must be satisfied that the appellant both knew that the drugs were under the couch and intended to exercise or assert control over them, either solely, or jointly with Cabral.
The appellant argued that the directions given as to proof of possession were generally confusing and, in some aspects, deficient. It was said that the directions concerning joint possession were confusing and inadequate and confused proof of a joint intention to sell the drugs with the concept of joint possession. Counsel argued that at no stage was it made clear to the jury that the prosecution needed to prove that the appellant had possession of the drugs located under the couch to the exclusion of all others ‘not acting in concert’ with her. It was suggested that the example given by the Judge – one relating to joint possession of shared items within a household – had the capacity to mislead.
The Judge’s general directions about proof of possession are now set out:
I move now to the concept of possession. As you are well aware, members of the jury, a real contest in this case, not the only one, but a real contest in this case is whether it has been proved that the accused was in possession of either drug. So I need to say more about the aspects of knowledge and possession. The first is this: a person is not to be regarded as being in possession of a substance for the purpose of this offence unless he or she knows of the existence of it. If one person slips an object into the pocket of another without the knowledge of that other person, then the latter cannot be said to be in possession of it, even though it may be in his or her pocket. In other words, there must be both physical control and an intention or ability to exercise control over the object. You can only do those things if you know it is there. If the accused did not know of the presence of the drugs under the couch, then she certainly cannot be in possession of them. To start with the prosecution must prove that she knew they were there.
Possession is something different from ownership. It is not necessary to own an object in order to possess it. For example, if you borrow someone’s trailer for the day to take some rubbish to the dump you are in possession of that trailer for that period of time that you have got it and before you return it. So you do not have to own something to possess it.
Many drug laws, particularly the one with which we are now dealing, concern an allegation of an offence whereby it is said that a person possessed the drugs. As I have said, the prosecution does not have to prove that she owned it, just merely that she possessed it knowingly for a certain purpose.
What does possession mean for the purposes of the charges? A person has possession of an object if he or she knowingly has physical custody or control of it. Control includes the power or ability to dispose of the object. He or she may have the object in his or her immediate possession, for example, in her hand, or she may have it in her pocket, or she may have it in a bag which is slightly removed from being directly in her hand. But, members of the jury, you have got possession. [I]f I pick up the pen here, I know I have got it and I am in possession of it, so in a loose sense legally it can be said that I am in possession of it. Alternatively, an accused person may have the object in a place where although he or she has not got immediate control over it, he or she has the exclusive right or power to place his hands or her hands on it. For example, if you have an object in a bag or a satchel nearby to where you are sitting now or even in your home. You may not be aware of it but - and it may be irrelevant for the purpose of this case - even though you are sitting here in court you are currently legally in possession of items back at your home or locked in your car in a carpark or in a satchel or bag that is nearby to you. Of course you may not be in exclusive possession of the item, it may be there are other members in your family or partners who are also in possession of it as well as you are. But you are certainly one of the people in possession of certain objects in your house or car or bag nearby to where you sit.
It follows from those matters that the need to prove that the accused possessed the drugs necessarily means that you would have to reject the possibility that the drugs were in the sole or exclusive possession of the man Cabral who was allowed by the police to leave. I will read that out again to you: it follows from those matters that the need to prove that the accused possessed the drugs necessarily means that you would have to reject the possibility that the drugs were in the sole or exclusive possession of the man Cabral.
It can be seen that in those passages the trial Judge specifically directed the jury that in order to prove the appellant possessed the drugs, they would have to reject as a reasonable possibility that the man Cabral had sole or exclusive possession of them. These directions conformed with guidance given in R v GNN (2000) 78 SASR 293. The comments of the Chief Justice in that case were of particular assistance and relevance to this case as the factual scenario in GNN was not dissimilar to the facts here. We do not consider that the example concerning a family situation was unhelpful. It served to explain how members of a household could share the possession of items without an express agreement concerning them.
The Judge went further, explaining to the jury that even if the appellant knew that Cabral had brought the drugs into the house and acquiesced in that, that this in itself would not be sufficient, unless she was in joint possession with Cabral.
He said:
I also need to give you this guidance: even if it is proved that the accused knew the drugs were brought to the house by Cabral and she acquiesced in that, that would not be sufficient for possession by her unless she was in joint possession of them with him. It would not be sufficient to prove possession by her if he brought them and hid them under the couch when he heard the police knocking and calling even if she knew he had so hidden them. In other words, members of the jury, if he brought them to the house and hid them when the police were heard to be knocking and possibly seen on the CCTV screen, even if she had known that he was doing that, does not make her in possession.
One way to prove possession by the accused is if you are satisfied she knew the drugs were hidden under the couch because she hid them there herself and was intending to exercise or assert control over them, or that the drugs were hidden there by Cabral at her request, she intending thereafter to assert control over them. I will just read that out to you again as well.
One way to prove possession by the accused is if you are satisfied she knew the drugs were hidden under the couch, because she had hidden them there herself, and was intending to exercise or assert control over them, or that the drugs were hidden there by Cabral at her request, she intending thereafter to assert control over them.
Another way of proving possession by her is if she and Cabral were in joint possession of the drugs so that one or other of them was going to sell at least some of the drugs.
I will read that out to you also. Another way of proving possession by her is if she and Cabral were in joint possession, that is they had something going between the two of them, such that the drugs were, by one or other of them, going to be sold or at least some of the drugs were going to be sold.
In those passages the Judge identified a number of ways in which the jury might arrive at a state of satisfaction that the appellant was in possession of the drugs. The first way was if the jury were satisfied that the appellant knew the drugs were hidden under the couch because she put them there and intended to assert control over them. Another way was if she knew that Cabral had put them there because she asked him to, she intending thereafter to assert control over them. A third route identified by the Judge was if the jury were to find the appellant and Cabral were in joint possession of the drugs, with one or other of them intending to sell. The Judge then went on to explain that joint possession could occur if both the appellant and Cabral were jointly involved in selling the drugs. However, he pointed out that in that situation the jury would need to be satisfied there was in fact a joint plan to sell.

Later, at the request of defence counsel, the trial Judge redirected the jury by expanding on the concept of joint possession. He explained that one way in which the prosecution pitched its case, although not a major one, was that both the appellant and Cabral knew the drugs were there, both the appellant and Cabral had control of the drugs and both the appellant and Cabral intended to sell them. That scenario, namely that they were in joint possession of the drugs with intent to sell, would be sufficient to prove possession for sale, even if it was Cabral who would do the selling. His Honour was careful to reiterate in the course of this redirection that before the jury could conclude that the two of them were in possession of the drugs running a drug selling business, first the jury must find that the two of them were in fact in joint possession.
He reminded them that if the appellant merely knew of and acquiesced in Cabral bringing the drugs into the house, that would not amount to possession. He then expanded on the idea of joint possession. He said:
Essentially what it means is, or may mean, depending on your interpretation of the facts, is that the two of them were in possession of these drugs running a drug selling business. Now whether that is the case is a matter for you, but that’s one of the ways in which the prosecution pitches its case. If both of them had physical custody and control of the drugs and both agree that they were going to sell them, it wouldn’t matter which was going to do the selling. But if there was an agreement between the two of them that they are going to sell the drugs or some of them then that would flow from their joint possession. But it would be necessary first of all for you to find that they were in fact in joint possession on the facts of the case.
One of the ways in which the prosecution has presented its case, although not a major way in which it has approached its case, is to say that they both knew the drugs were there, they both had control of the drugs, they both intended to sell as or pursuant to an agreement between the two of them that that be done by one or other of them. If that was the case, that is they were in joint possession, then that would be sufficient to prove possession for sale even if it was Mr Cabral who was going to do the selling. So any intention to sell held by either of them would be sufficient if there was an agreement to that effect.
Counsel argued that the direction suggesting that one way of proving possession by the appellant was by proving that they were in joint possession for the purpose of one or other selling the drugs was simply wrong. He suggested that what was required in order to prove joint possession was proof that the appellant and Cabral were “acting in concert on the issue of possession, not the issue of an intention to sell”. He referred to the New South Wales Court of Criminal Appeal decision of Dib & Dib v The Queen (1991) 52 A Crim R 64. There the appellants, who were husband and wife, had been found guilty of a joint charge of supplying heroin, the case being one of deemed possession for supply based on their possession of a trafficable quantity. The heroin was found in the kitchen of the house occupied by the appellants and their children. Each appellant claimed exclusive possession of it. The Crown alleged a joint enterprise. At the time of the discovery other adults were present at the house. Two of them possessed different quantities of heroin.
The particular passage relied on by counsel for the appellant in the present case was a statement by Hunt J, who speaking for the Court, said, at 67:
Where (as in the present case) the Crown seeks to establish an accused’s possession of property found not within his manual possession but rather in premises to which he has access, it must – in order to establish beyond reasonable doubt that it was the accused rather than anyone else who had such possession of that property – persuade the jury that the accused has the legal right to exclude all persons from the premises in which the property is situated (other than those acting in concert with him). In a case where two or more accused are alleged to be in joint possession of the property, the Crown must establish that they all had that legal right.
Counsel stressed the use of the phrase ‘other than those acting in concert with him’.
It can readily be seen that the concept of acting in concert could be usefully employed in a context where the prosecution asserts that the two accused were jointly in possession of a quantity of the relevant substance for the purpose of supplying it. However, as a general rule, we do not think introduction of the idea of a joint enterprise into an explanation of the concept of joint possession would be helpful. It is noteworthy that Hunt J approved the initial direction given by the trial Judge on possession and joint possession, despite it containing no reference to acting in concert or a joint enterprise. We do not understand the Court to be saying in the quoted passage that such a reference is ordinarily required.
Here the prosecution case was primarily that the appellant, alone, possessed the drugs. The drugs were in her house and immediate control. However, the jury were entitled to consider the possibility that she and Cabral were in joint possession of them. They would have been in joint possession of them if they each had knowledge of the location of the drugs and intended, between them, to exercise control over them, to the exclusion of any other persons. We do not consider that the Judge was really saying any more than this. No doubt, proof of as much would imply some agreement, spoken or unspoken, either in relation to this particular cache of drugs, or perhaps in relation to some earlier edition. But proof of a joint enterprise between them, that is, that they were acting in concert as to the future disposition of the particular drugs is not essential to proof of possession itself. Indeed, we would not encourage the application of the use of the words ‘acting in concert’ to the concept of possession. It is unnecessary. We are not suggesting that there would have been anything wrong, in technical terms, with a direction which included the notion of acting in concert as to future sales; but that direction would be unnecessary and would add complexity.
In fact, as seen, the Judge did explain that a factual scenario which could account for joint possession included an agreement that one or other of them would sell the drugs. He said that such an agreement would explain why they might both have physical custody and control. It was an explanation which tended to draw together all the circumstances of the prosecution case. But at no stage did the Judge invite the jury to infer possession from a demonstrated agreement to sell. On the contrary, the Judge repeatedly stressed the jury was required first to find that there was joint possession.
In our view it was appropriate for the Judge to so direct the jury as, on the evidence, that was one realistic scenario which arose for its consideration.
Strictly speaking, we do not consider it was necessary for the trial Judge to have acceded to the request for redirection on the topic of possession, however he was prepared to do so. We consider that the directions given in the summing up proper were sufficient.
As acknowledged in argument the legal concept of possession is a difficult one to explain to a jury. However in our view the trial Judge’s directions on this topic were adequate. His Honour identified the possibilities which might arise for the jury’s consideration. He then directed the jury appropriately about those different scenarios in accordance with the principles enunciated in GNN. In our view those directions were adequate to give the jury the assistance they realistically needed when considering the circumstances which arose for their consideration. Nothing further was required.
For these reasons we would not uphold this ground of appeal.
Validity of Regulations
With respect to this ground of appeal we have had the advantage of reading in draft the reasons of White J. We agree with his Honour’s reasons for concluding that the appellant’s challenge to the validity of regulations under the Controlled Substances Act 1984 (SA) which specify an amount of a mixture for the purposes of the definition of a “trafficable quantity” of a controlled drug, must fail. For the reasons given by White J we would not uphold this ground of appeal.
Unreasonable Verdict
A proposed ground of appeal to the effect that the verdict of guilty was unreasonable and could not be supported having regard to the evidence was referred to this Court without permission having been granted.
The argument in support of it focussed on the suggested difficulty in finding beyond reasonable doubt on the basis of all the evidence that the appellant knew of the position of the drugs under the couch, and that she intended to assert control over them in the future. It was argued that this difficulty flowed from the fact that, at the time the police entered the house, Cabral was in the lounge room. It was put that there was nothing to exclude an explanation in terms of Cabral placing the drugs there as soon as he realised police were on the premises. Counsel pointed to the appellant’s denial to police of knowledge of the drugs and to the fact that no fingerprints or DNA of hers were located on the containers in which they were found as well as to a number of items of circumstantial evidence which, he submitted, supported the appellant’s denial of being in possession of the drugs.
We cannot accept this submission. As set out earlier in these reasons, there were important pieces of evidence linking the appellant to the drugs under the couch. There was the appellant’s admitted ownership of the Betty Boop tin, the fact that she used methadone bottles of the same type as the one found and her use of Winfield cigarettes. Additionally there was her possession of packaging similar to that in which the drugs were located. There was a large quantity of cash in her handbag and in her bedroom in large denominations, just as there was in the Winfield cigarette packet. There were other trappings of a drug operation in and about the house, of itself raising a strong suspicion of the appellant using the premises as a point of sale. Cabral’s presence there and admitted links to the appellant and his DNA being found on one of the methadone bottles in the bag was clear evidence that he, too, was involved in that enterprise.
In our view, the jury was clearly entitled to conclude on the basis of the entirety of the evidence that the appellant was selling drugs from her house, either on her own account, or with Cabral.
The ground of appeal has no substance. We would refuse permission to appeal on this ground.
Conclusion
In our view, the appeal must be dismissed.
WHITE J: The appellant was convicted by the majority verdicts of a jury on two counts of trafficking in a controlled drug, in contravention of s 32(3) of the Controlled Substances Act 1984 (SA) (“CSA”). Both offences were alleged to have been committed on 28 July 2008. Count 1 alleged trafficking in heroin, and Count 2 trafficking in methylamphetamine.
A person may “traffic” in a controlled drug in three different ways: by selling the drug; by possessing the drug with the intention of selling it; or by taking part in the process of sale of the drug.[1] In the appellant’s case, the prosecution allegation was that she had possession of the heroin and methylamphetamine with the intention of selling them.
[1] See the definition of “traffic” in s 4(1) of the CSA.
A Judge granted the appellant permission to appeal against her conviction on two grounds, and referred to this Court the request for permission to appeal on the ground that the jury verdicts were unreasonable.
The Prosecution Case
Police went to the appellant’s home at Kilburn at about 7.45pm on 28 July 2008 and conducted a search. The appellant and a friend of hers, Mr Cabral, were in the house at the time. Mr Cabral was searched and allowed to leave.
Shortly afterwards, the police found underneath a couch in the lounge room a love‑heart shaped tin, a small brown bottle, and a Winfield Blue cigarette packet. The appellant admitted to the police that the tin was hers. It contained 12 small plastic wrapped balls, described by counsel as bindles, each of which contained a white substance later analysed as including heroin. The total weight of the substance in the 12 bindles was 2.17gms, of which 0.43gms was pure heroin. That is, the heroin had a purity of approximately 20 per cent. This heroin was the subject of Count 1.
The appellant also acknowledged to the police that the small brown bottle was one of her methadone bottles. Within the bottle were 11 small re‑sealable plastic bags, nine of which contained methylamphetamine. The total weight of the mixture in the bags was 3.83gms, of which 1.36gms was pure methylamphetamine (a purity of approximately 35 per cent). These drugs were the subject of Count 2.
The Winfield Blue cigarette packet contained $1,140, mostly in $50 notes. Although the appellant denied knowledge of the money, she admitted that she smoked Winfield Blue cigarettes.
It was common ground at trial and on appeal that both heroin and methylamphetamine are controlled drugs as defined in the CSA.
The prosecution case that the appellant had possession of the heroin and the methylamphetamine, whether by herself or jointly, was based wholly on circumstantial evidence. The prosecution relied on evidence that the house at Kilburn was the appellant’s home, and that apart from her daughter, no-one else lived there. It was common ground that Mr Cabral lived elsewhere, although the appellant told police that he spent time with her at the house. The house had a closed circuit television (“CCTV”) with a single camera filming the area near the front door and relaying live images to a small television monitor in the lounge room. There was evidence that CCTVs are commonly used at premises occupied by those in the drug trade.
The bindles of heroin were of a kind commonly sold in street deals. There was evidence that bindles of the kind found are commonly placed inside water balloons for protection. Some balloons of this kind were found in the love-heart shaped tin and packets of these balloons were found in the appellant’s kitchen. The appellant acknowledged that the balloons were hers, although she told police that she had them for children’s birthday parties.
In addition to the money found in the Winfield Blue cigarette packet, the police found other cash in the house. A purse in the appellant’s handbag contained $1,280 in notes. A bag in a red tin in the appellant’s bedroom contained $6,510, mostly in $50 and $100 note denominations. The appellant acknowledged that both the red tin and the cash were hers. Other evidence indicated that these large amounts of cash could not be related to banking transactions, or to the appellant’s employment. The prosecutor submitted that the money was the proceeds of drug trading, and provided a motive for the appellant’s possession of the drugs. The appellant gave the police an innocent explanation for the presence of the money but the prosecutor submitted that that explanation should be rejected.
A piece of “Minnie Mouse” tape removed from the brown bottle matched a piece of tape stuck on the notes found in the bag contained in the red tin. Some seven mobile phones, two of which were operable, were found in the house. A police drug investigation expert gave evidence that it was common for multiple mobile phones to be used by those engaged in drug dealing.
Fingerprint and DNA tests did not produce any results consistent with those of the appellant. However, a DNA swab taken from one of the re‑sealable bags found inside the brown bottle “matched” that of Mr Cabral.
Empty re‑sealable bags of the kind found in the brown bottle were also found in the appellant’s car, but the appellant did tell police that Mr Cabral and another man frequently used her car. Finally, the appellant acknowledged that she had previously used heroin, and was familiar with the way in which street deals were commonly packaged.
The appellant did not give evidence at the trial. The admissions and acknowledgements to which I have just referred were made by her when interviewed by the police after her arrest.
The critical issue at trial was whether the prosecution had proved the appellant’s possession of the heroin and methylamphetamine. The appellant submitted that each of the pieces of circumstantial evidence relied upon by the prosecution could be regarded as having an innocent, or at least a neutral, explanation, and that the prosecution case at its highest could not exclude, as a reasonable possibility, that it was Mr Cabral who had been in possession of the drugs. These submissions formed the basis of the appellant’s contention that the jury verdicts were unreasonable.
In addition, the appellant complains of the adequacy of the Judge’s directions concerning the concept of possession and contends that a regulation upon which the prosecution relied in invoking a statutory aid to proof was invalid.
Validity of Regulations
As the prosecution case was that the appellant had possession of the heroin and methylamphetamine with the intention of selling them, it had to satisfy the jury of the appellant’s intentions in that respect. For this purpose, the prosecution relied upon some of the circumstantial evidence outlined above and, in addition, on the statutory aid to proof contained in s 32(5) of the CSA. That subsection provides:
(5)If, in any proceedings for an offence against subsection (1), (2) or (3) it is proved that the defendant had possession of a trafficable quantity of a controlled drug, it is presumed, in the absence of proof to the contrary—
(a) in a case where it is alleged that the defendant was taking part in the process of sale of the drug, that the defendant—
(i)was acting for the purpose of sale of the drug; and
(ii)had the relevant belief concerning the sale of the drug necessary to constitute the offence; or
(b) in any other case—that the defendant had the relevant intention concerning the sale of the drug necessary to constitute the offence.
If the prosecution proves that a defendant had possession of a “trafficable quantity” of a controlled drug, the effect of s 32(5) is to require that defendant to satisfy the Court on the balance of probabilities that he or she did not have possession of the relevant drug for the purpose of sale.
The appellant submitted that that part of the regulations made under the CSA which defines a “trafficable quantity” of heroin and methadone for the purposes of s 32(5) is invalid, with the effect that it had not been open to the prosecution to rely upon the statutory aid to proof in her trial.
Relevant Statutory and Regulatory Provisions
Section 32 of the CSA has been in its present form since 3 December 2007.[2] The counterpart statutory aid to proof provision in the former s 32, which was also s 32(5), was interpreted as requiring defendants to satisfy the Court on the balance of probabilities that they did not possess the relevant drug or substance for the purposes of sale.[3] The appellant did not suggest that s 32(5) in its present form should be construed any differently. If the trier of fact is satisfied beyond reasonable doubt in a case like the present that a defendant had possession of “a trafficable quantity” of a controlled drug then it is to be presumed, in the absence of proof to the contrary, that the defendant had possession of the drug with the intention of selling it.
[2] The current form of s 32 was introduced into the CSA by s 14 of the Controlled Substances (Serious Drug Offences) Amendment Act 2005 (SA).
[3] R v Zampogna [2003] SASC 75 at [43]-[44]; (2003) 85 SASR 56 at 64-5; R v Granger [2004] SASC 156 at [7], [17]; (2004) 88 SASR 453 at 457, 459.

A definition of the expression “trafficable quantity” was first introduced into s 4(1) of the CSA by the Controlled Substances (Serious Drug Offences) Amendment Act 2005 (SA). The definition was amended with effect from 10 September 2009 by s 4(3) of the Controlled Substances (Controlled Drugs, Precursors and Cannabis) Amendment Act 2008 (SA). However, it is the definition in its original form which was applicable as at 28 July 2008. That definition provided:
Trafficable Quantity of a controlled drug or controlled plant means –
(a) in relation to a controlled drug contained in a mixture –
(i)a quantity of the drug which equals or exceeds the amount prescribed as a trafficable quantity for the drug in its pure form; or
(ii)a quantity of the mixture that equals or exceeds the amount (if any) prescribed as a trafficable quantity for any mixture containing the drugs; or
(b) in any other case – a quantity of the drug or plant that equals or exceeds the amount prescribed as a trafficable quantity for the drug or plant (as the case may be) in its pure form.
It can be seen that sub-paragraph (a) of the definition relates to controlled drugs contained in a mixture, while sub-paragraph (b) relates to drugs or plants in their pure form. When the drug is contained in a mixture, a trafficable quantity will be that quantity of the drug which is not less than the amount prescribed for the drug in its pure form, or the quantity of the mixture which is not less than the amount prescribed for any mixture containing the drug.
In the present case, each of the heroin and the methylamphetamine found at the appellant’s house formed part of a mixture. Accordingly, it was sub‑paragraph (a) of the definition of “trafficable quantity” which applied in the appellant’s case. The prosecution relied upon sub-paragraph (a)(ii). This meant, in effect, that each of the heroin and methylamphetamine found in the appellant’s house would be a trafficable quantity if the mixture in which each was contained was not less than the quantity prescribed for any mixture containing those drugs.
The Controlled Substances (General) Regulations 2000 (the Regulations) made under the CSA do prescribe a quantity for the purposes of sub-paragraph (a)(ii) of the definition of “trafficable quantity”. As at 28 July 2008, reg 6(6) provided as follows:
(6)For the purposes of the definition of trafficable quantity in section 4(1) of the Act, the quantity of a mixture containing a particular controlled drug prescribed as a trafficable quantity for any mixture containing the controlled drug is the amount (if any) listed in the column headed "Trafficable (mixed)" of the tables in Part 1 or 2 of Schedule 1 opposite the entry listing the controlled drug.
Part 1 of Sch 1 of the Regulations contains a list of controlled drugs other than drugs of dependence together with a specification of the quantity of each of those drugs for a number of purposes of the CSA. In relation to heroin, it specifies 2 grams as the quantity of a mixture containing heroin for the purposes of the definition of “trafficable quantity”.
Part 2 of Sch 2 lists a number of drugs of dependence, including methylamphetamine, as well as the quantity of the listed drugs for a number of purposes of the CSA. It specifies 2 grams as the quantity of a mixture containing methylamphetamine for the purposes of the definition of a “trafficable quantity” of a mixture containing methylamphetamine.
In summary, the quantity prescribed in the Regulations for a mixture containing either heroin or methylamphetamine is 2 grams. The effect of s 32(5) and of the Regulations therefore is that if a trier of fact is satisfied that a defendant had possession of at least 2 grams of a mixture of which part was either heroin or methylamphetamine, the defendant is to be presumed to have possession of that drug with the intention of selling it, unless the defendant proves the contrary. This would be so even if the controlled drug comprised a relatively minor proportion of the overall mixture.
The Regulations do not contain any specification of a “trafficable quantity” of either heroin or methylamphetamine in their pure form, which probably reflects the fact that these drugs are invariably adulterated when sold in small quantities.
Regulation 6 and Sch 1 of the Regulations were made by the Governor under s 63 of the CSA. Section 63 provides relevantly:
(1)The Governor may make such regulations as are contemplated by, or as are necessary or expedient for the purposes of, this Act.
(2)The Minister must consult with the Advisory Council in relation to any regulation proposed to be made under this Act (other than a regulation proposed to be made under section 33LA).
(3)No regulation may be made prescribing an amount relating to a controlled drug, controlled precursor or controlled plant for the purposes of Part 5 or section 45A except upon the recommendation of the Advisory Council.
…
(6)Any regulation under this Act may be of general or limited application according to—
(a)     the classes of persons or things; or
(b)     the circumstances; or
(c)     any other specified factor,
to which the regulation is expressed to apply.
The appellant did not contend that there had been any formal or procedural defect by the Governor in the making of the Regulation. Nor did she contend that it was not open to the Governor to make regulations specifying quantities of mixtures containing drugs for the purposes of the definition of a “trafficable quantity”. It is the specification of mixtures of 2 grams as trafficable quantities of heroin and methylamphetamine which the appellant contends is invalid. The argument was that the specification of such small amounts is so unreasonable, irrational or unreasonably disproportionate to the purposes of the CSA as not to be a valid exercise of the regulation making power.
The appellant did not contend that the aggregation of the amounts of heroin in the bundles, or of the amounts of methylamphetamine in the plastic bags, so as to produce amounts exceeding 2 grams was inappropriate.
The Principles Concerning the Invalidity of Delegated Legislation
Delegated legislation may be held invalid either because it is an unreasonable exercise of the authorising power, or because it is not reasonably proportionate to the purpose sought to be achieved by the enabling legislation. [4] There is a considerable overlap between these two grounds of invalidity[5] and the parties’ submissions on the present appeal did not really distinguish between them. A number of the authorities were reviewed recently by Besanko J in Guo v Minister for Immigration and Citizenship [6]
[4] De Silva v Minister for Immigration and Multicultural Affairs (1998) 89 FCR 502 at 510.
[5] Guo v Minister for Immigration and Citizenship [2009] FCA 356 at [35]; (2009) 176 FCR 83 at 92.
[6] [2009] FCA 356; (2009) 176 FCR 83.
In general, a challenge on the grounds of a want of reasonable proportionality may be available when a delegate is authorised to make a form of delegated legislation in order to achieve the purposes of the enabling legislation. The authorising legislation may identify those purposes in specific or general terms. There are however some authorities which suggest that the test of reasonable proportionality may be more apt when the delegated legislation is authorised by the statute for a particular purpose, as distinct from the general purposes of the statute.[7]
[7] Nationwide News Pty Ltd v Wills (1992) 177 CLR 1 at 89 (Dawson J).
The High Court considered a claim of invalidity on the basis of a lack of proportionality in State of South Australia v Tanner.[8] The majority (Wilson, Dawson, Toohey and Gaudron JJ) said:
In the course of argument, the parties accepted the reasonable proportionality test of validity …, namely, whether the regulation is capable of being considered to be reasonably proportionate to the pursuit of the enabling purpose. … The same test, in relation to a power limited to regulation, was expressed by Dixon J in Williams, as being, in substance, whether the regulation goes beyond any restraint which could be reasonably adopted for the prescribed purpose.[9]
Later, the majority said:
… A court must exercise care not to impose its own untutored judgment on the legislator … It is not enough that the court itself thinks the regulation inexpedient or misguided. It must be so lacking in reasonable proportionality as not to be a real exercise of the power.[10]
[8] (1988) 166 CLR 161.
[9] Ibid at 165.
[10] Ibid at 168.
The judgment of Dixon J to which the majority in Tanner referred is that in Williams v Melbourne Corporation.[11] Dixon J said:
To determine whether a by-law is an exercise of a power, it is not always enough to ascertain the subject matter of the power and consider whether the by-law appears on its face to relate to that subject. The true nature and purpose of the power must be determined, and it must often be necessary to examine the operation of the by-law in the local circumstances to which it is intended to apply. Notwithstanding that ex facie there seemed a sufficient connection between the subject of the power and that of the by-law, the true nature of the by-law may then appear to be such that it could not reasonably have been adopted as a means of attaining the ends of the power. In such a case the by-law will be invalid, not because it is inexpedient or misguided, but because it is not a real exercise of the power.[12]
[11] (1933) 49 CLR 142.
[12] Ibid at 155.
In Minister for Resources v Dover Fisheries[13] Cooper J explained the difference between invalidity on the ground of a want of proportionality, on the one hand, and on the ground of unreasonableness, on the other, in the following terms:
The test of proportionality reflects an underlying assumption that the legislature did not intend that the power to enact delegated legislation would be exercised beyond what was reasonably proportionate to achieve the relevant statutory object or purpose. The test of reasonableness assumes that the legislature did not intend to confer a power to enact delegated legislation which enactment no reasonable mind could justify as appropriate and adapted to the purpose in issue and the subject matter of the grant.[14]
However, as Cooper J himself noted, there is considerable overlap between the tests of proportionality and reasonableness. However one describes the test, “the object is to find the limit set by the legislature for the proper exercise of the regulation or rule-making power and then to measure the substantive operation of the delegated legislation by reference to that limit”.[15] Gummow J in Dover Fisheries expressed the proposition similarly when he said:
The fundamental question is whether the delegated legislation is within the scope of what the Parliament intended when enacting the statute which empowers the subordinate authority to make certain laws.[16]
[13] (1993) 116 ALR 54.
[14] Ibid at 75.
[15] Ibid.
[16] Ibid at 66.
The final matter to note before turning more specifically to the appellant’s submissions is the stringency of the test of unreasonableness which the courts apply in this context. Diplock LJ in Mixnam’s Properties Ltd v Chertsey UDC[17] expressed the proper approach in a way which has been followed by a number of Australian authorities:
Thus, the kind of unreasonableness which invalidates a by-law is not the antonym of “reasonableness” in a sense in which that expression is used in the common law, but such manifest arbitrariness, in justice or partiality that a court would say “Parliament never intended to give authority to make such rules; they are unreasonable and ultra vires”.[18]
Thus a litigant who claims that delegated legislation is invalid on the grounds of unreasonableness faces a formidable task. The cases in which delegated legislation have been held to be invalid on these grounds are rare.[19]
[17] [1964] 1 QB 214.
[18] Ibid at 237.
[19] Guo v Minister for Immigration and Citizenship [2009] FCA 356 at [35]; (2009) 176 FCR 83 at 92.
Consideration of Proportionality and Reasonableness
Section 63(1) of the CSA vests a regulation-making power in the Governor for the general purposes of that Act, rather than for some specific identified purpose. The Governor may make “such regulations as are contemplated by, or as are necessary or expedient” for the purposes of the CSA. That being so, the question is whether the specifications in Sch 1 of the Regulations are capable of being considered reasonably proportionate to the achievement of the purposes of the CSA.
It may be accepted, as a matter of principle, that the specification by the Executive of very minor quantities of a drug, or of a mixture containing a drug, may not be a valid exercise of the regulation-making power. That is because the amounts specified may be so low as to give the presumption contained in s 32(5) an unreasonable or irrational operation. Whether the specification of a particular quantity of a drug is to be characterised in that way requires an evaluation of a number of matters, including the nature of the drug and the circumstances in which it is distributed and used.
The appellant sought to establish the unreasonableness of the specification of 2 grams and for heroin and methylamphetamine in Sch 1 of the Regulations in a variety of ways.
First, she contended that, having regard to the purpose of the definition of “trafficable quantity”, Parliament must have contemplated that the Regulations would prescribe a quantity of pure drug, or a quantity of a mixture containing a drug, which is likely to be possessed for the purposes of sale, rather than for personal use. In support of this submission, the appellant referred to the observations of Cox J in R v Turner[20] in relation to s 5(4) of the Narcotic and Psychotropic Drugs Act 1934 (SA), a predecessor provision to s 32(5) of the CSA:
It seems clear to me that Parliament, in enacting sub-s (4), contemplated that the Executive would, by regulation, and in reliance upon the expert knowledge of those advising it, determine a quantity with respect to a particular drug, having in mind the ordinary experience of drug users and, most important, the quantity of that drug that they are likely to possess for personal use as against a possession for the purpose of trade. In other words, what they are saying here is that, where a man has a particular quantity of a specified drug in his possession, then experience shows that it is reasonable to infer from that very quantity, in the absence of proof to the contrary, that his purpose in possessing the drug is a commercial purpose and not a private one.[21]
The observations of Cox J concerning that provision are of course of considerable weight in the present context. However, I do not understand Cox J to be suggesting a simple dichotomy between amounts likely to be kept for private use and amounts kept for sale. There is a third category, namely those amounts which are consistent with both private use and trade purposes which Parliament may also be taken to have intended should be subject to the s 32(5) presumption.
[20] (1980) 24 SASR 217.
[21] Ibid at 220.
In my opinion, it is appropriate to conclude that Parliament intended that the Regulations would exclude from the definition of a “trafficable quantity” those amounts which experience suggests are probably possessed for private use only, but not those amounts which are consistent with both personal and commercial purposes, and not those larger amounts which are likely to be possessed for commercial purposes. Section 32(5) is intended to assist the prosecution in overcoming the difficulties of proof involved in establishing a defendant’s purpose in possessing a controlled drug. That being so, it is likely that the Parliament intended that the prosecution should have that assistance both in relation to quantities which are consistent with either personal or commercial purposes, as well as in relation to those quantities which, of their size and nature, are likely to be possessed for commercial purposes. Put slightly differently, Parliament can be taken to have intended that, unless the quantity of the controlled drug is no more than that typically associated with personal use, it is the possessors of the drugs who should be required to prove that they did not have a commercial purpose.
In any event, as Cox J observed, Parliament contemplated that the Executive would, with the assistance of expert advice, have regard to the evidence of the amounts of drugs which are ordinarily possessed for personal use on the one hand, and, on the other, trade purposes. Accordingly, the approach outlined by Cox J in Turner serves only to focus the enquiry and does not, by itself, suggest unreasonableness or lack of proportionality. I will refer shortly to the inferences which can be drawn from the evidence of the Police Drug Investigation Officer at the appellant’s trial, but I observe at this point that the appellant’s bare assertion that mixtures of less than 2 grams were “clearly” not indicative of a commercial purpose does not, by itself, advance the matter. That is especially so given that small amounts of drugs may be contained in multiple packages for the purposes of trading.
Next, the appellant submitted that if the prescribed quantities of mixtures are set at unrealistically small amounts, low level users of controlled drugs who have no commercial involvement will, by virtue of s 32(5), be presumed to be traffickers. This would have the effect of courts imposing criminal sanctions on such low level users which would be disproportionate to the true criminality of their conduct. The Parliament should not be understood as having intended that a regulation could be made which would produce this result. In this way, the appellant sought, in effect, to invoke the proportionality principle.
The premise to this submission is an assumption that the prescribed quantities of mixtures set out in Sch 1 of the Regulations are at unrealistically low levels. Presenting the submission in that way tends to suggest its own answer, but it says nothing about what levels may be regarded as “unrealistically low”. Moreover, as was pointed out by Doyle CJ in Granger “it should not be overlooked that, the lower the amount of cannabis in question, the easier it should be for an accused person to rebut the statutory presumption”.[22]
[22] R v Granger [2004] SASC 156 at [58]; (2004) 88 SASR 453 at 471.
Finally, the appellant contrasted the specified quantity of 2 grams for a mixture containing heroin and methylamphetamine with the amounts specified before 3 December 2007. Regulation 6 and Sch 2 of the Controlled Substances (Prohibited Substances) Regulations 2000 (SA) and reg 31K(1) and Sch KA of the Controlled Substances (Poisons) Regulations 1996 (SA) prescribed amounts of heroin and methylamphetamine respectively for the purposes of s 32(5) of the CSA in its previous form. In each case, the prescribed amount was 2 grams, and this was a specification of each drug in its pure form.[23] It was said that regulations which purport to fix the amount of a mixture containing a controlled drug in the same quantity as was previously fixed for the pure form of the same drug are unreasonable. Implicit in this submission was the further submission that the specified amount for a mixture should be higher than the amount specified for the drug in its pure form, so as to make allowance for the fact that a mixture, by definition, will contain a smaller amount of the drug.
[23] R v Mason [2000] SASC 161 at [73]; (2000) 77 SASR 105 at 121.
It is natural to suppose that the prescribed amount of a mixture would be higher than that for the drug in its pure form, but I do not consider that this submissions take the matter much further. The fixing by the Executive in 2000 and in 1996 of 2 grams as the prescribed amount of heroin and methylamphetamine respectively for the purpose of s 32(5) in its then form, can be taken to have been a reasonable exercise of the regulation-making power at that time. However, it does not follow that the fixing, some seven years later, of the same weight as the prescribed amount of a mixture containing those drugs for the purposes of the new s 32(5) is unreasonable. In the first place, the specification of 2 grams in 1996 and 2000 says nothing at all about whether some smaller amount could also have been reasonably prescribed at that time. Secondly, it is to be expected that the amount prescribed for the purposes of s 32(5) may vary from time to time, as account is taken of the contemporaneous practice in, and knowledge of, drug use and the drug trade.

The possible invalidity of the Regulations specifying an amount for the purpose of the definition of a “trafficable quantity” was first raised on the appeal. Accordingly, no evidence was led at trial of the circumstances known at the time the Regulations were made concerning drug use and the drug trade. However, as part of its case, the prosecution did lead evidence, including expert evidence, from Sgt Gillan, a police officer with experience in drug investigations. Sgt Gillan gave evidence about some aspects of the street level dealing in, and the use of, heroin and methylamphetamine in 2008. Some of that evidence bears upon the challenge to the reasonableness and proportionality of the Regulations now made by the appellant.
Sgt Gillan said that in 2008, heroin and methylamphetamine were almost always sold by weight and, at street level, nearly always in an adulterated form. He said that typically the heroin used in 2008 had a purity of about 20 per cent, meaning that it was sold and used in a heavily adulterated form. The mixture containing the heroin would be sold in weights of 0.1 gram, 0.2 grams, 0.3 grams, 1 gram and 1 ounce. The 0.1 gram, 0.2 gram, 0.3 gram and 1 gram weights would typically be sold at prices of the order of $50, $100, $150, and between $300 and $400 respectively.
Sgt Gillan said that methylamphetamine was commonly sold in the streets in a form ready for use in weights of 0.1 gram containing 10 per cent or less of pure methylamphetamine. Users would commonly use the methylamphetamine in that form. Methylamphetamine was also sold in mixtures weighing 1 gram, 3.5 grams and 1 ounce. In 2008 it was unusual for users to use methylamphetamine of approximately 35 per cent purity, ie, of the kind found in the appellant’s home. There was some variability in the price of methylamphetamine in 2008, with mixtures weighing 0.1 gram selling on the street for between $30 and $100, mixtures of 1 gram selling for between $250 and $300, mixtures of 3.5 grams selling for between $500 and $1,500, and mixtures of 1 ounce selling for between $2,700 and $9,500, with the price in all cases depending upon the purity of the mixture.
On the basis of Sgt Gillan’s evidence, it can be seen that in 2008, a mixture of 2 grams containing heroin of 20 per cent purity could be used to make up some 20 deals. Those deals would very valuable as they may fetch in total an amount of the order of $1,000 in street level dealing. Furthermore, the greater the purity of the heroin in a 2 gram mixture, the greater the possibility of further adulteration and therefore the larger the number of deals which could be derived from it.
In the case of methylamphetamine, a mixture of 2 grams of 10 per cent purity could also be used to make up 20 deals. Again, the greater the purity of the methylamphetamine in the mixture, the larger the number of deals which could be derived from a 2 gram amount. 20 deals of methylamphetamine would also be valuable, being likely to fetch between $600 and $2,000 on the street.
Sgt Gillan did not give any evidence about the number of deals which a user who was not engaged at all in selling may have in his or her possession at any one time. However, ordinary experience suggests that it is unlikely that the typical user would have 20 deals of either heroin or methylamphetamine, or the capacity to make up such a large number of deals, in their possession at any one time. At the least, it cannot be concluded that a conclusion by the regulation-maker that the possession of a 2 gram mixture of heroin or methylamphetamine was consistent with a commercial purpose was unreasonable or irrational. Nor can it be concluded that the specification of 2 grams in these circumstances is disproportionate to the purposes sought to be achieved by the CSA.
These considerations indicate, by themselves, that the appellant’s claim of unreasonableness, irrationality or lack of proportionality in the specification in Sch 1 of the Regulations of mixtures of 2 grams for heroin and methylamphetamine must fail.
I note one further matter. By virtue of s 63(2) and (3) the Governor cannot make a regulation specifying an amount relating to a controlled drug for the purposes of s 32(5) except upon the recommendation of the Advisory Council established under s 6 of the CSA. It is apparent that the Advisory Council consists of a number of persons with relevant experience in the effects of drugs which may be made subject to the CSA and in the monitoring, review and control of such drugs. Given that Sch 1 of the Regulations could only have been made upon the recommendation of the Advisory Council, this Court should be slow, in my opinion, to hold that the specification of the amount of a mixture containing heroin or methylamphetamine was unreasonable or irrational.
For these reasons, I consider that the appellant’s challenge to the validity of the Regulation specifying an amount of a mixture for the purposes of the definition of a “trafficable quantity” of a controlled drug fails.
Directions as to Possession
The appellant submitted that the Judge failed to direct the jury adequately and correctly with respect to the concept of possession.
As has been said many times, possession is an elusive legal concept which can be difficult to explain to a jury.
Section 4(1) of the CSA contains a definition of the word “possession” which was amended with effect from 3 December 2007.[24] The definition applies to the use of the word “possession” in s 32 of the CSA. Prior to 3 December 2007, “possession” was defined as follows:
Possession of a substance includes control over the disposition of the substance.
Since 3 December 2007 “possession” has been defined as follows:
Possession of a substance or thing includes –
(a) having control over the disposition of the substance or thing; and
(b) having joint possession of the substance or thing.
It can be seen that both definitions are of the inclusive type. It is not clear what purpose is served by the definition, as it does not seem to add to, nor confine, the concept as developed by common law.
[24] Controlled Substances (Serious Drug Offences) Amendment Act 2005 (SA), s 4(5).
The basic concepts of possession are not in doubt. Persons have possession of an item if they have physical custody or control of the item or of the place in which it is located, knowledge that the item is in their custody or control, and an intention to control the item. Walters J in R v Frangos described this intention as “the intention of exercising power of control over it to the exclusion of others”[25]). It is the application of those concepts in cases, like the present, in which the item in question is in a place to which persons other than the accused also have, or may have had, access which presents difficulties in directing a jury properly.
[25] (1979) 21 SASR 331 at 339.
The circumstances disclosed by the prosecution evidence in this case suggested a number of possibilities concerning the possession of the heroin and methylamphetamine. Those possibilities included that the appellant did have exclusive possession of each of the drugs; that the appellant and Mr Cabral had joint possession of each of the drugs; that Mr Cabral had possession of each of the drugs but had placed them under the couch with the appellant’s knowledge for safe keeping; and that Mr Cabral had possession of the drugs and had put them under the couch without the appellant being aware at all that that had occurred. In the first two instances, the appellant could properly be found to have been in possession of both drugs. In the latter two instances, the appellant could not be held to have had possession of the drugs.
Given the various possibilities, the directions to the jury had to explain adequately the concept of possession, by the appellant alone, and jointly with Mr Cabral. The jury had to be told that they had to be satisfied that the drugs were not in the exclusive possession of Mr Cabral; that mere knowledge by the appellant of the presence of the drugs was insufficient;[26] and that they had to be satisfied that the appellant intended to exercise control over the drugs.[27]
[26] Lai v The Queen (1990) WAR 151 at [155]; He Kaw Teh v The Queen (1985) 157 CLR 523 at 538 per Gibbs CJ.
[27] R v GNN [2000] SASC 447 at [20], (2000) 78 SASR 293 at 296; R v Moubarak [2002] SASC 110 at [18]-[21], (2002) 219 LSJS 276 at 278-80; R v Davis (1990) 50 A Crim R 55 at 61, 65.
The Directions
The Judge commenced his directions on the topic of possession with some general instructions of a conventional kind. I have numbered the relevant paragraphs in the summing-up for ease of further reference:
1.So I need to say more about the aspects of knowledge and possession. The first is this: a person is not to be regarded as being in possession of a substance for the purpose of this offence unless he or she knows of the existence of it. If one person slips an object into the pocket of another without the knowledge of that other person, then the latter cannot be said to be in possession of it, even though it may be in his or her pocket. In other words, there must be both physical control and an intention or ability to exercise control over the object. You can only do those things if you know it is there. If the accused did not know of the presence of the drugs under the couch, then she certainly cannot be in possession of them. To start with the prosecution must prove that she knew they were there.
The Judge then explained that possession was different from ownership and gave the following further directions:
2.What does possession mean for the purposes of the charges? A person has possession of an object if he or she knowingly has physical custody or control of it. Control includes the power or ability to dispose of the object. He or she may have the object in his or her immediate possession, for example, in her hand, or she may have it in her pocket, or she may have it in a bag which is slightly removed from being directly in her hand. But, members of the jury, you have got possession, if I pick up the pen here. I know I have got it and I am in possession of it, so in a loose sense legally it can be said I am in possession of it. Alternatively, an accused person may have the object in place where although he or she has not got immediate control over it, he or she has the exclusive right or power to place his hands or her hands on it. For example, if you have an object in a bag or satchel nearby to where you are sitting now or even in your home. You may not be aware of it – and it may be irrelevant for the purpose of this case – even though you are sitting here in Court you are currently legally in possession of items back at your home or locked in your car in a carpark or in a satchel or bag that is nearby to you. Of course, you may not be in exclusive possession of the time, it may be there are other members in your family or partners who are also in possession of it as well as you are. But you are certainly one of the people in possession of certain objects in your house or car or bag nearby to where you sit.
3.It follows from those matters that the need to prove that the accused possessed the drugs necessarily means that you would have to reject the possibility that the drugs were in the sole or exclusive possession of the man Cabral who was allowed by the police to leave. [The Judge then repeated that direction].
4.I also need to give you this guidance: even if it is proved that the accused knew the drugs were brought to the house by Cabral and she acquiesced in that, that would not be sufficient for possession by her unless she was in joint possession of them with him. It would not be sufficient to prove possession by her if he brought them and hid them under the couch when he heard the police knocking and calling even if she knew he had so hidden them. In other words … if he brought them to the house and hid them when the police were heard to be knocking and possibly seen on the CCTV screen, even if she had known that he was doing that, does not make her in possession.
5.One way to prove possession by the accused is if you are satisfied that she knew the drugs were hidden under the couch because she hid them there herself and was intending to exercise or assert control over them, or that the drugs were hidden there by Cabral at her request, she intending thereafter to assert control over them. [The Judge then repeated that direction]
6.Another way of proving possession by her is if she and Cabral were in joint possession of the drugs so that one or other of them was going to sell at least some of the drugs.
7.I will read that out to you also. Another way of proving possession by her is if she and Cabral were in joint possession, that is they had something going between the two of them, such that the drugs were, by one or other of them, going to be sold or at least some of the drugs were going to be sold.
When the jury retired, counsel for the appellant sought a re-direction concerning the topic of joint possession. The Judge then gave the jury these further directions:
8.… In the main part of my summing-up I said …: even if it is proved that the accused knew the drugs were brought to the house by Cabral, and she acquiesced in it, that would not be sufficient for possession by her unless she was in joint possession of them with him. I also said this to you: another way of proving possession by her is if she and Cabral were in joint possession of the drugs so that one or other of them was going to sell at least some of the drugs. Let me just expand upon the aspect then of joint possession. That is hers and Cabral’s.
9.Essentially what it means is, or may mean, depending on your interpretation of the facts, is that the two of them were in possession of these drugs running a drug selling business. Now whether that is the case is a matter for you, but that is one of the ways in which the prosecution pitches its case. If both of them had physical custody and control of the drugs and both agreed that they were going to sell them, it wouldn’t matter which was going to do the selling. But if there was an agreement between the two of them that they are going to sell the drugs or some of them then that would flow from the joint possession. But it would be necessary first of all for you to find that they were in fact in joint possession on the facts of the case.
10.One of the ways in which the prosecution has presented its case, although not a major way in which it has approached its case, is to say that they both knew the drugs were there, they both had control of the drugs, they both intended to sell as or pursuant to an agreement between the two of them that that be done by one or other of them. If that was the case, that is they were in joint possession then that would be sufficient to prove possession for sale even if it was Mr Cabral who was going to do the selling. So any intention to sell held by either of them would be sufficient if there was an agreement to that effect.
Later, the jury asked the Judge to define again the concept of possession, preferably in writing. The Judge then provided the jury with an extract of the text of his original summing-up and read those paragraphs to the jury. This included the directions in the paragraphs numbered 1 to 7 above, but not the directions in the paragraphs numbered 8 to 10. The Judge did not otherwise elaborate in the further re-direction on the concept of possession and did not repeat what he had said during the first re-direction.
Consideration of Submissions
The appellant submitted first that the Judge’s directions omitted the requirement for the jury to be satisfied that she intended to control the drugs. I do not accept that submission. It overlooks what the Judge said on the topic of intention in the paragraphs numbered 1 and 5. It is possible that the reference to “an intention or ability to exercise control over the object” in paragraph 1 may have been confusing, but the position was clarified by the direction in paragraph 5 (which was repeated by the Judge).
Next, the appellant complained of the Judge’s directions in paragraph 2 concerning the possession of an object which is not in the person’s immediate physical control but in a place over which the person does have control. The Judge gave as an example the items which jurors possessed which were located in their own homes. The submission was that the direction that the jurors were in possession of the items in their own home even while sitting in Court was inappropriate because it may have led the jury to reason that, on the same basis, the applicant was in possession of the drugs found in her home.
In my opinion, this submission involves an overly literal understanding of the Judge’s direction. It overlooks that the direction was given as part of the Judge’s elaboration of his direction that possession involves a person “knowingly” having physical custody or control of the object.
The appellant’s principal complaint related to the Judge’s directions concerning joint possession, set out in summing-up paragraphs 6 to 10. There were a number of facets to the complaint.
The appellant submitted first that for two persons to have joint possession of an item, they must be acting in concert. It was said that this required proof of an arrangement or understanding between them, amounting to an agreement that they would have joint control over the disposition of the item. It was said that the Judge had erred by failing to direct the jury to consider whether the evidence satisfied them that the appellant and Mr Cabral had an agreement or understanding to this effect.
The appellant founded this submission on statements in the authorities to the effect that several persons may in concert have exclusive possession as against the rest of the world[28] and to the effect that possession requires that a person have present physical control of the items in question “to the exclusion of others not acting in concert”.[29] The expression “acting in concert” is commonly used in the law relating to joint enterprise under which two or more persons who reach an understanding that, together they will commit a crime and, while that understanding is on foot, one or other of them does the acts necessary to complete the crime, will be equally guilty of that crime irrespective of the part which each played in its commission. This led counsel to argue that the notion of two or more persons acting in concert for the purposes of joint possession required proof of some understanding or arrangement between them amounting to an agreement that they would have joint control over the item in question.
[28] Moors v Burke (1919) 26 CLR 265 at 271, 274.
[29] Borrillo v Bartlett [1966] SASR 286 at 287.
However, I do not understand the expression “acting in concert” in relation to the concept of joint possession, to be used with its joint enterprise meaning or, at least, not entirely so. Joint possession is the possession of an article by two or more persons. It exists when two or more persons have joint control over the one article. The concept was described by Mayo J in Borrillo v Bartlett:
Joint possession of an article may be had by two or more persons. It is joint when each person has a share in possessory rights, and the article is in a place that is accessible, perhaps equally accessible, to all. Joint possession does not involve, as it were, fractional rights in the object, or equal rights to some fractional part of the object, but rights to the totality.[30]
[30] Ibid at 288.
Persons have joint possession if they share possession of the item in question. “Acting in concert” is simply a way of describing the sharing of control.[31] No doubt the sharing of control will often have a basis in some agreement, tacit or otherwise, but the critical feature is the shared control, and not the antecedent agreement.
[31] R v Wan [2003] NSWCCA 225 at [14]; (2003) 140 A Crim R 513 at 517.

This being so, it was not necessary for the prosecution to prove, as a separate matter, some arrangement or understanding between the appellant and Mr Cabral in relation to possession of the drugs. This particular complaint concerning the Judge’s directions therefore fails.
However, other complaints of the appellant concerning the directions on the topic of joint possession have more substance.
The Judge told the jury that it was open to them to convict the appellant if they were satisfied that she and Mr Cabral had joint possession of the drugs (summing-up paragraphs 6 and 7). However, apart from one passage to which I will refer shortly, the Judge did not explain the concept of joint possession to the jury in terms of shared possessory rights,[32] or in terms of joint control.[33] The direction in summing-up paragraph 6 did not explain the concept of joint possession at all and, insofar as it linked the concept of joint possession to an intention by either the appellant or Mr Cabral to sell at least some of the drugs, may well have confused the jury. The repetition of the direction in summing-up paragraph 7 did not clarify the position.
[32] Borrillo v Bartlett [1966] SASR 286 at 288.
[33] R v Davis (1990) 50 A Crim R 55 at 67.
It is not clear what the Judge meant by his reference in paragraph 7 to the appellant and Mr Cabral having “something going between the two of them” but, on any view, it was not a direction which directed the jury to the concepts involved in shared possession or shared control of the drugs. Counsel for the Director on the appeal acknowledged that the direction in summing-up paragraph 7 did not explain the concept of joint possession to the jury.
Further, the direction in paragraph 7 again linked the issue of joint possession with the intention of either the appellant or Mr Cabral. In the way in which it was framed, the direction tended to conflate a joint intention to sell the drugs, on the one hand, with joint possession of the drugs, on the other. The Judge may have been intending to direct the jury that satisfaction that the appellant and Mr Cabral intended jointly to sell the drugs could be used to infer either joint possession, or at least, possession by the appellant. However, the different onuses of proof in relation to possession, and commercial purpose made directions to this effect quite difficult. If the purpose of the alleged possession is to be used as part of the proof of possession itself, it must be made clear to the jury that it is the prosecution which has the onus, and that the presumption in s 32(5) cannot be used for this purpose. In practice, directions to this effect may be quite difficult, and it may be preferable in most cases for this path of reasoning to be avoided.
In his first re-direction the Judge did attempt to explain the concept of joint possession further. In paragraph 9, he did refer to joint possession in terms of the appellant and Mr Cabral both having physical custody and control of the drugs. However, when this direction is read as a whole, it can be seen that the Judge has again conflated the notions of joint possession and joint intention to sell. This is particularly seen in the first sentence of paragraph 9 when the Judge said:
Essentially what [joint possession] means is, or may mean, depending on your interpretation of the facts, is that the two of them were in possession of these drugs running a drug selling business.
By this passage, the jury were directed that it was appropriate to consider the question of joint possession of the drugs by reference to joint participation by the appellant and Mr Cabral in a drug selling business. The direction diverted the jury from considering the possibility that the appellant and Mr Cabral may have had joint possession of the drugs but without any intention to sell at all.
Apart from any other consideration, the different burdens of proof required that these issues be kept separate. It was for the prosecution to prove beyond reasonable doubt that the appellant had possession of the drugs, either exclusively, or jointly with Mr Cabral. Once that was established, it was for the appellant to prove an absence of commercial purpose. The Judge’s direction linking the concept of possession with the concept of commercial purpose had the potential therefore to lead the jury to use the presumption concerning commercial purpose in reaching its conclusion about possession.
The Judge did give a clearer direction in the first sentence of paragraph 10 but, in the second sentence again linked the concept of joint possession to the purpose of the possession.
As the re-direction in response to the jury question was effectively a repetition of the directions in paragraphs 1 to 10, it did not correct the inadequacies in the summing-up.
On this basis I consider that the appellant’s submission that the Judge’s directions on the topic of possession were inadequate has been made out. In many respects, the issue of possession was the issue at trial. It is evident that the jury was concerned about it. Even after the first re-direction, the jury sought further assistance on the concept. I note also that it returned majority verdicts. In these circumstances, I do not consider that this is a case for application of the proviso. In consequence, the appeal should be allowed.
Unreasonable Verdict
As noted at the outset of these reasons, the appellant’s request for permission to appeal on the ground that the jury verdicts were unreasonable was referred to this Court. Having regard to my conclusions concerning the adequacy of the Judge’s directions, it is neither necessary nor appropriate to consider this application.
Conclusion
For the reasons given above, I would allow the appeal. I would set aside the two convictions and direct a re-trial.