Ciara Glennon More than a decade after Ms Glennon’s death, Macro taskforce detectives received a breakthrough in the triple-murder investigation when a male’s DNA profile was recovered from one of the victim’s bodies for the first time. Debris from Ms Glennon’s left thumbnail – collected at her post-mortem and marked in a sealed container as ‘debris only, not suitable for analysis’ – was eventually tested in a UK-based lab in 2008 after being combined with a sample from her left middle fingernail. The low copy number testing revealed a mixed DNA profile consistent with coming from Ms Glennon and a male profile which matched an unsolved Karrakatta cemetery rape case from a year before the murders began. It took detectives another eight years to discover the profile belonged to Mr Edwards after the reopening of a 1988 cold case sex attack uncovered another item with his DNA on it.

Mr Edwards originally denied the sex attack and rape when arrested in late 2016 but admitted to the crimes in 2019, a month before his murder trial commenced. His lawyer Paul Yovich claims that in the 11 years between Ms Glennon’s murder in 1997 and the DNA breakthrough in 2008, Mr Edwards’ DNA – which was stored at Pathwest within the 1995 rape exhibits – somehow contaminated one or both of the fingernail clippings known as AJM40 and AJM42. “The defence accepts that the mixed DNA profile extracted from the sample that became AJM 40 and 42 is consistent with a two-person profile, the contributors of which are Ms Glennon and the accused,” he said in his opening statement. “The defence also accepts that the likelihood of a chance match between the male component of that mixed profile and the accused's profile is very low – the numbers quoted range from in the order of 80 million to one to 100 million. “[Mr Edwards] does not know how DNA matching his profile came to be part of this sample and no breaches or failures of lab protocol or procedure have been documented that directly explain it.”

With no evidence of when the contamination occurred, Mr Yovich has questioned every witness who worked for Pathwest in the 1990s about their anti-contamination protocols in an attempt to show lab processes during the early stages of DNA testing were not adequate to prevent trace DNA cross-contamination. He claimed Mr Edwards’ DNA most likely made its way into Ms Glennon’s fingernail exhibit through secondary transfer – when DNA is transferred from one object to another through an intermediate, such as a bench or piece of laboratory equipment like forceps or a scientist’s glove. It is this type of contamination which likely led to a branch taken from Ms Rimmer's crime scene being contaminated with the DNA profile of an unrelated victim whose exhibits were tested in the Pathwest lab in the days either side of the Macro exhibit in 2002. The branch is among seven Macro-related exhibits that were contaminated between 1996 and 2003 while in the Pathwest lab.

Five items were found to be contaminated with the DNA of at least three Pathwest scientists including intimate swabs taken from Ms Rimmer and Ms Glennon, fingernail samples taken from Ms Rimmer and two branches taken from Ms Rimmer’s crime scene. The defence alleges Mr Edwards DNA contaminated Ms Glennon's fingernail exhibits while in the Pathwest lab. Credit:Cameron Myles The seventh item was a negative control sample used in a DNA test that was later found to have been contaminated with a female’s DNA. The identity of the female the DNA belonged to was never pursued. Mr Yovich has also hinted through his cross-examination of two Pathwest employees that it’s possible Mr Edwards, a former Telstra technician who mostly worked for the telco’s government and business clients, may have at some stage serviced the telephones inside the secure DNA section of the lab. “We accept the scientific literature suggests that the chance of contamination in a lab is usually remote although secondary transfer is known and documented in the literature,” Mr Yovich said.

“Your Honour will have to consider just how remote the chance was here and whether it can be safely ruled out even if it was remote.” Bradley Edwards in the 1990s. Mr Edwards is being tried by judge alone, with Justice Stephen Hall to decide his fate at the end of the trial, which is tipped to run for another three to six months. Prosecutor Carmel Barbagallo has described the defence’s DNA contamination theory as “fantasy” and claimed it ignored the evidence of the case. "DNA doesn't just fly through a laboratory, it cannot get through plastic," she said.

"The mechanisms and the opportunity simply doesn't exist in the objective facts of the case. "At no time did the [Karrakatta rape victim's] exhibits occupy the same bench, box or shelf as Ciara Glennon's." Pathwest forensic scientist Anna-Marie Ashley, who was involved in the DNA testing of Ms Glennon’s exhibits and the Karrakatta rape victim’s exhibits, has given evidence at trial stating the closest timeframe between the Karrakatta rape exhibits and Ms Glennon’s fingernail clippings being tested was two weeks. It is expected the state will finish its DNA evidence within the coming weeks, at which point it will then move onto its fibre evidence which it claims links Mr Edwards to the murders of Ms Rimmer and Ms Glennon and the Karrakatta rape through common fibres found at each crime scene.