The defence honed in on potential DNA contamination from samples sent to a lab in New Zealand on day 40 of WA’s trial of the century.

During cross examination, defence lawyer Paul Yovich pointed out to Dr SallyAnn Harbison, who was on the stand for a second day, that when testing Ciara Glennon’s fingernail samples, four blank control samples were found to be contaminated with another woman’s DNA.

Forensic DNA expert Brendan Chapman joins us for this episode, and as he explains, this isn’t a ‘blow’ for the prosecution, and that was because, although the court heard two fingernail samples AJM 41 and 46 had been affected by contamination and showed a woman’s DNA unrelated to the case - Dr Harbison said the crucial left middle fingernail - AJM 42, which the state says contained Bradley Edwards’ DNA - was not affected by the contamination.

Brendan helps the podcast team discuss contamination, DNA and even a bit of ancestry on episode 40, he also answers some of your complex DNA questions, which have come up during the trial and left us scratching our heads.

If you have any questions for Brendan or any of the podcast team and guests, send them in to [email protected].

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