The Queensland Police Service trusted the advice from a government-run forensic laboratory, which drove changes that resulted in thousands of pieces of crime scene evidence going tested.

A Commission of Inquiry into Forensic DNA Testing heard on Thursday that senior officers in charge of the police DNA unit had only a limited understanding of DNA testing.

Superintendent Dale Frieberg, Operations Commander of the Forensic Services Group, told the inquiry she didn’t have scientific qualifications and didn’t understand the testing changes proposed by the Forensic and Scientific Services lab.

The lab introduced changes to DNA threshold limits to save time and money and improve efficiency, which meant that from early 2018 thousands of crime scene samples weren’t tested.

“I wouldn’t have understood it the way in hindsight I should have understood it,” Supt Frieberg admitted to the inquiry.

Documents tendered to the commission show Supt Frieberg agreed with the changes, which she told the inquiry had been influenced by advice from Queensland Health.

“I guess as part of my role as a superintendent, and you know, in any government department, it’s about relationships,” she said.

“It’s about trust.

“We (the Queensland Police Service) paid $3 million a year to Queensland Health to provide us with expert advice … the options paper has come from people who are experts, and I trusted that advice.”

The $3 million was part of the annual police budget for forensic laboratory services, the…