The prosecution appears to have briefed several experts regarding stab wound interpretation. By Jeff’s second trial, only three of these were called to give evidence before the jury. The evidence they gave at trial is directly contradicted by published scientific research.
Expert Witnesses
Expert witnesses are a special type of witness. They are the only witnesses allowed to give opinions as evidence in a court, based on their training and experience. Their duty is meant to be to the Court, rather than to one side or the other. They are not meant to be “hired guns” and they should not give opinion evidence outside of their recognised field of training or expertise.
For guidelines on the role and responsibilities of experts please see http://www.austlii.edu.au/au/legis/nsw/consol_reg/scr1970232/s75.3j.html and http://www.austlii.edu.au/au/legis/nsw/consol_reg/ucpr2005305/sch7.html.
The Crown’s use of stab wounds experts
The three experts called by the prosecution to give evidence at Jeff’s second trial all presented opinions that the wounds to all three victims were similar. The prosecution chose to only present these opinions to the jury. The expert opinions were provided without reference to any existing research or literature on stab wounds.
The judge ruled that expert witnesses were allowed to give their opinions about the similarities of the stab wounds, but these witnesses were not permitted to draw any conclusions about what this meant.
However, the crown prosecutor presented her own conclusions to the jury, using the expert opinions to argue that the similarities demonstrated a single perpetrator.
Where did the other experts go?
A fourth “expert” who had spoken in dramatic terms about Jeff’s case on the 60 Minutes Program in 1997, was called to give evidence at Jeff’s first trial but he was not asked to give further evidence presumably because he disclosed to the Court that his only experience on multiple stab wounds involved just one case – involving an attack on a man and his dog.
The fifth expert, who is internationally recognised as a leading forensic pathologist, disagreed with the other experts. At Jeff’s trial the prosecution refused to call him to give evidence, claiming he was “plainly unreliable”.
It appears that a further expert, the prosecution’s sixth, was also approached. When asked by Jeff’s lawyers for a copy of this report, the Director of Public Prosecutions denied that a report was obtained from this expert.