Forensic scientist tells inquiry of contaminated bone samples and rusty tools at DNA testing lab

A forensic scientist has told DNA testing inquiry that she noticed her DNA profile results started returning tainted after November 2020 which she alleges coincided with the introduction of a new cleaning procedure by someone without appropriate expertise.

A specialist DNA scientist has told an Inquiry testing of bone samples at a state-run lab began returning contaminated results after a new cleaning procedure was introduced by someone without expertise who didn’t consult qualified specialists.

The Forensic Scientific Services’ Angelina Keller, who specialises in analysing samples, said the testing of bones and teeth from dead bodies was an accurate and consistent method to identify Deoxyribonucleic acid, or DNA, profiles.

In her 16-years operating in the highly specialised field of the forensic lab, she said testing of bones had always returned a single-source DNA profile.

But, Ms Keller told a commission of inquiry into DNA testing at the Queensland Health Forensic and Scientific Services (QHFSS) lab, that from November 2020, her results started to be tainted with the return of mixed DNA profiles.

“Since then, it has happened more frequently,” she said.

A forensic scientist told a commission of inquiry into DNA testing at a state run lab that her results started to be tainted with the return of mixed DNA profiles after November 2020. She told the inquiry a new cleaning procedure for some of the specialised equipment had been introduced by someone without expertise who didn’t consult qualified specialists. Picture: Supplied

She also showed the inquiry a spreadsheet that outlined how mixed DNA samples had returned in about half the tests conducted between late 2020 and August this year.

The scientist told the hearing, at the Brisbane Magistrates Court, on Tuesday that when she noticed the contamination, she thought: “’We’ve got a problem, we’ve got to find out what’s going on.’”

“It was concerning me greatly,” she said.

The purpose of the inquiry, which started on June 13, is to examine a decision made in 2018 to not further test samples with low levels of DNA, resulting in thousands of pieces of evidence from crimes like rape and murder being ignored.

This week the inquiry topics to be covered in the public hearings relate to the culture of the state-owned laboratory and how this has impacted on various scientific issues, according to inquiry documents.

Ms Keller told the hearing she uses a range of tools to dissect bone samples from unidentified bodies to extract DNA samples, which she said had lately become rusty.

She provided a submission to the inquiry detailing how a change to how bone crushing equipment was cleaned was introduced in July 2019.

A commission of inquiry into DNA testing at the Queensland Health Forensic and Scientific Services is being held at the Brisbane Magistrates Court on George St in the city this week. Picture: John Weekes

The equipment is used in the process of examining remains to assist the coroner and police to identify remains from missing persons investigations and disasters such as plane crashes and fires.

“As far as I am aware,” she wrote in her submission.

“There was no validation or verification performed to confirm bleach and/or trigene followed by 70 per cent ethanol can effectively clean the remaining equipment.”

Ms Keller told the hearing she is conducting tests to conclude if the cleaning change was the source of the contamination, but she said this and two other introduced actions correlated with the highly unusual pattern of bone samples returning mixed DNA profiles.

The other two changes in the lab included a change to the extraction process of the samples and the technique to store the samples.

The Commission of Inquiry into DNA testing at the QHFSS was established to ensure transparency, identify opportunities for improvement and ensure public confidence in the collection of DNA and the testing and analysis undertaken in Queensland, and in the criminal justice system more broadly, according to Queensland Health documents.