FOUR scientists contaminated evidence in the Claremont serial killings case with their own DNA, Western Australia’s so-called trial of the century has heard.
Bradley Robert Edwards, 51, denies murdering Sarah Spiers, 18, Jane Rimmer, 23, and Ciara Glennon, 27, in 1996 and 1997, with his lawyers claiming his DNA may have ended up on Ms Glennon’s fingernails due to contamination.
PathWest scientist Andrew McDonald, who used to work for Cellmark Forensic Services in the UK where exhibits were tested after Edwards’ 2016 arrest, testified in the WA Supreme Court on Thursday.
Mr McDonald said DNA from former PathWest lead scientist Laurie Webb and his colleagues Aleksander Bagdonavicius, Louise King and Scott Egan had been found on samples, including vegetation and swabs taken from Ms Rimmer and Ms Glennon.
DNA from Steven Daventhoren, who found a knife near Ms Rimmer’s body, was also on a sample.
Mr Webb, who was sacked from PathWest in 2016 for breaching testing protocols, has not taken the stand but five statements from him were previously read out in court.
Ms King has testified she did not recall any lapse of procedures.
Mr Bagdonavicius has told the court female police officers were requested to assist to reduce the risk of male contamination.
Mr Egan testified on Thursday that when tradespeople visited the lab they would sign in at reception, but there was no record of Edwards in the visitor books dating back to 1995.
Defence counsel Paul Yovich previously raised the possibility of work being done on phone lines in the lab.
Earlier this week, a senior detective testified the case took a turning point in 2008 after scientists at the UK’s Forensic Science Service found a male DNA profile on a combined sample of two of Ms Glennon’s fingernails.
The male profile matched an unsolved cemetery rape case but was not linked to Edwards until years later.
The former Telstra technician admits raping a 17-year-old girl he abducted and dragged through Karrakatta cemetery in 1995 and attacking an 18-year-old woman as she slept in her Huntingdale home in 1988.
The epic six-month trial, which is at day 53, continues.