Yesterday the High Court delivered two judgments.
The first was the Court’s reasons for allowing the appeal and directing that a judgment and verdict of acquittal be entered in Fitzgerald v The Queen  HCA 28. In that case the appellant was convicted of murder, and an aggravated offence of causing serious harm. The prosecution case was that the appellant and his co-accused were members of a group that forced entry into a house, and that each member of the group was a party to a common plan to cause grievous bodily harm to persons inside the house. The issue in the appellant’s trial was the sufficiency of the evidence to establish that he was one of the group. The prosecution relied on DNA evidence obtained from a sample taken from a didgeridoo found at the crime scene to establish that fact. The High Court held that the forensic evidence of Dr Henry, called by the prosecution, did not establish beyond reasonable doubt that the appellant’s DNA in the sample was derived from the appellant’s blood. That then left the issue of how the DNA came to be on the didgeridoo. Dr Henry’s evidence was to the effect that a primary transfer is a much more likely source of contact or trace DNA than a secondary transfer, but that nevertheless a secondary transfer of contact or trace DNA is possible. There was no conflict in the evidence that there were at least two distinct occasions on which a secondary transfer of the appellant’s DNA to the didgeridoo may have occurred. The recovery of the appellant’s DNA from the didgeridoo did not raise any inference about the time when or circumstances in which the DNA was deposited there. For those reasons, the High Court held that it could not be accepted that the evidence relied on by the prosecution was sufficient to establish beyond reasonable doubt that the appellant was present at, and participated in, the attack. Alternative hypotheses consistent with the appellant’s innocence, in particular the hypothesis that his co-accused transferred the appellant’s DNA to the didgeridoo on during a visit to the house on the day in question, were not unreasonable and the prosecution had not successfully excluded those hypotheses.
The second was the judgment in Honeysett v The Queen  HCA 29. In that case the appellant was convicted of the armed robbery of an employee of a suburban hotel. CCTV recorded the robbery. At the trial, over objection, the prosecution adduced evidence from an anatomist, Professor Henneberg, of anatomical characteristics that were common to the appellant and to one of the robbers. Professor Henneberg’s opinion was based on viewing the CCTV images of the robbery and images of the appellant taken while he was in custody. The question for determination was whether or not the evidence of Professor Henneberg “involved an area of specialised knowledge based on training, study or experience” and whether Professor Henneberg’s opinion was wholly or substantially based on that area of specialised knowledge. In the High Court, the only specialised knowledge relied upo by the Crown was Professor Henneberg’s is knowledge of anatomy. The Crown argued that Professor Henneberg did not give evidence in the trial of identification based on anatomical comparison. Rather, his evidence was no more than an account of the characteristics of the body of the person depicted in each set of images: it was evidence of opinion wholly or substantially based on Professor Henneberg’s specialised knowledge of anatomy. However, the High Court held that Professor Henneberg’s opinion was not based on his undoubted knowledge of anatomy. Professor Henneberg’s knowledge as an anatomist, that the human population includes individuals who have oval shaped heads and individuals who have round shaped heads (when viewed from above), did not form the basis of his conclusion that the robber and the appellant each have oval shaped heads. That conclusion was based on Professor Henneberg’s subjective impression of what he saw when he looked at the images. His opinions about right-handedness, were also not based upon his expertise in handedness, but on his observations that the robberne used his right hand to remove cash from the till and the appellant used his right hand to write his name and insert a swab into his mouth. Professor Henneberg’s evidence gave the unwarranted appearance of science to the prosecution case that the appellant and the robber shared a number of physical characteristics. Among other things, the use of technical terms to describe those characteristics – the robber and the appellant are both ectomorphic – was apt to suggest the existence of more telling similarity than to observe that each appeared to be skinny. It should therefore not have been admitted.