R v Pfennig

This case concerned an appeal against a conviction for murder, where the central plank of the prosecution's circumstantial case was DNA evidence. The applicant argued that if the DNA evidence were disregarded, the remaining circumstantial evidence was insufficient to prove guilt beyond a reasonable doubt. The appeal was heard by Blue J.

The legal issues before the court included whether the DNA evidence, specifically concerning its analysis and interpretation, was sufficiently reliable to prove guilt beyond reasonable doubt. A further issue was whether the possibility of innocent secondary transfer of the applicant's DNA to the victim's pyjama top had been adequately excluded by the prosecution's evidence. The court also considered the relevance of likelihood ratios in DNA analysis and whether the scientific evidence could preclude innocent transfer under various factual scenarios.

Blue J reasoned that it was open to the trial judge to accept the results of the DNA testing, both NFI and FSSA, in relation to the tapelift and fluff samples as proved beyond reasonable doubt. The judge found that the circumstantial evidence, when considered alongside the DNA evidence, confirmed the conclusion that the applicant's DNA was on the pyjama top, and this was proved beyond reasonable doubt. The court referenced *R v Doheny and Adams* to highlight that the significance of DNA evidence is critically dependent on other known facts about the suspect, such as their proximity to the crime scene. Regarding the secondary transfer argument, the court considered the particulars raised by the applicant, including the prosecution's evidence of possible factual scenarios for transfer and the inability of scientific evidence to preclude such transfer.

The court concluded that the first limb of the proposed ground of appeal, concerning the sufficiency of the evidence without the DNA, was not reasonably arguable. Permission to appeal was not granted on this basis. The court's decision on the second limb, concerning innocent secondary transfer, is not fully detailed in the provided text, but it appears to have been considered in conjunction with the overall evidence.