Andrew L. Urban.
Robert Xie’s barrister, Belinda Rigg SC, continued on Day 2 of the hearing to pull apart the expert evidence around the DNA, arguing to the appeal court that the uncertainty of forensic testing outcomes were never properly and clearly put to the jury. The evidence presented had “the capacity to mislead the jury”.
It was not made clear to the jury at the trial, Rigg told the court, that the DNA of Brenda Lin could not be excluded from the DNA mix, a crucial factor since Brenda (the daughter of the murdered couple) was overseas at the time of the killings, hence the DNA mixture could not be relevant to the crime.
The DNA sample was in a small deposit (2cm x 6 mm) of uncertain material on Robert Xie’s garage floor, 300 metres from the crime scene. But the court is tangled entirely in the statistical labyrinth that characterises the challenge of this DNA sample.
There has been no examination so far at the appeal of when was it deposited? Or how? This, of course, is absolutely fundamental to the evidence being at all relevant. It is mere impermissible speculation without the evidence that it was deposited AFTER the murders. It was not found at the crime scene but the garage where the two families often played together, providing many opportunities to leave their DNA, directly or by transfer. The prosecution suggested at one stage that it may have been deposited from the murder weapon as it was placed on the floor of the garage before it was disposed. But no such weapon was presented to the jury.
Perhaps these questions will come up later in the appeal hearing, which continues.