Shandee’s Story podcast: Did lab check DNA of high-priority targets?

Queensland lab may have failed to conduct DNA comparison checks on two high-priority targets in the Shandee Blackburn murder investigation.

Forensic scientist Kristy Wright with Shandee Blackburn’s sister Shannah and mother Vicki. Picture: Lyndon Mechielsen

Queensland’s government-run forensics laboratory may have failed to conduct DNA comparison checks on two high-priority targets in the Shandee Blackburn murder investigation.

Scott MacPherson had a history of using knives to stab and menace people, and was once jailed after violently assaulting Blackburn’s mother, Vicki.

Homicide detectives had MacPherson and his friend Isaiah Corowa on a list of six high-priority persons of interest in Blackburn’s 2013 murder, along with her former boyfriend John Peros, local criminal William Daniel and his cousin Norman Dorante, and another man.

Episode 13 of Shandee’s Story is the last for the year.

Forensic scientist Kirsty Wright has been unable to find any trace of DNA from MacPherson or Corowa being compared with any DNA profiles from the crime scene or on Blackburn’s body and clothes.

These profiles did not meet the criteria to upload to a national DNA database so they relied on matching using the Queensland lab’s processes.

“There’s just no evidence the lab ever compared two of the six suspects to their crime scene samples – nothing for Corowa or MacPherson, even though their samples were sent as suspect samples,” Dr Wright said.

She found the potential bombshell anomaly while reviewing forensics evidence for investi­gative podcast series Shandee’s Story, and alerted police several weeks before the latest episode.

MacPherson became a person of interest as someone who lived near the murder scene, was a known drug abuser, did not have a reliable alibi and was ­previously involved in the attack on Vicki, with her daughter Shandee Blackburn present. Claims emerged during the police investigation that he hung out near the Girl Guides hut where the killer hid before the ­attack, and that Blackburn’s missing handbag was seen at his house.

Detectives ruled out MacPherson and Corowa as suspects, as did Coroner David O’Connell in his inquest findings last year.

However, police and the coroner would have had a reasonable expectation that DNA profiles of the two short-listed persons of interest were compared by lab scientists with crime scene DNA.

Barrister Craig Eberhardt, representing Peros, questioned MacPherson at the inquest about his convictions for violence, including the stabbing of a woman in the face and breast.

MacPherson accepted he had a lot of entries on his criminal history for assaulting people, breaking into houses, stealing, assault and carrying a knife, but couldn’t remember Vicki Blackburn confronting him after she found him in her yard.

Vicki Blackburn says she found MacPherson armed with a stick in her yard, approaching Shandee and her cousin.

“He went to take a step towards the girls and I stepped in front of him then, and that’s when he punched me,” she said. “He hit me, punched me, and I fell to the ground.”

Vicki Blackburn was later told he pleaded guilty to assault and numerous unrelated charges and was jailed.

An incident involving MacPherson “going berserk” with a knife while drunk made Mac­kay’s Daily Mercury newspaper in 2007. The article described him breaking two knives trying to stab and kick his way through a locked door. He eventually managed to cut and bash his way through with a third knife. His friend Corowa also had an extensive criminal history. Both deny any involvement in Blackburn’s murder.

About 85 samples were tested from Shandee Blackburn, her clothing and mobile phone, with 19 DNA profiles generated that contained DNA from unknown persons.

These are the profiles that may not have been compared with the DNA from MacPherson and Corowa.

Shandee’s Story will return in early 2022 with new episodes and new leads.