An inquiry has heard “no thinking” was required by scientists at Queensland’s forensics lab when analysing crime scene samples for DNA.

An inquiry is underway in Brisbane examining a 2018 change in processes at Queensland Health’s Forensic and Scientific Services laboratory for testing of crime scene evidence containing extremely small amounts of DNA.

Commissioner Walter Sofronoff KC said the lab was run like a production line where DNA analysts would process a sample without knowing whether it was blood, semen, or saliva “because that would involve time taken to think”.

“Nobody is required to apply any thought or context to the work they’re doing except to get the technical side of it done correctly,” Mr Sofronoff said.

“So absolutely no thinking apart from ensuring the work has been done correctly according to scientific standards.”

Evidence recovery and quality team leader Paula Brisotto was cross examined about the process, admitting scientists in the analytical team would not look at photos of the sample source.

“That’s not what they were trained to do,” Ms Brisotto said.

That sparked a tense exchange.

“No that’s not what they’re trained to do and that’s because it would take time to do it, and you as the person responsible for that team don’t want them to take time to do it,” Mr Sofronoff said.

“You want them to get the results out, whatever they are? Good or bad, reliable or not reliable, just get them out,” he said.

“No,” Ms Brisotto replied.

“Well explain then why your staff aren’t required to do something as basic as look at the photos? What’s the reason for that?” Mr Sofronoff said.

“The reason — it is not built into the forensic register,” Ms Brisotto said.

Mr Sofronoff cut her off: “I know. What is the reason?”

“The reason is it’s not something they’ve done in the past,” Ms Brisotto said.

“So you haven’t thought about it have you?” Mr Sofronoff asked.

“No I haven’t,” Ms Brisotto said.

The inquiry was shown a photograph of a blood splatter from which a sample was found to contain “no DNA”.

“Do you think if scientists were routinely checking the photographs before they validated a sample as ‘no DNA’ or ‘insufficient DNA for further processing’, that that would be more likely to cause them to re-test something like that?” Counsel Assisting Michael Hodge KC asked.

“Yes, they might in assessing that sample and other samples in the case,” Ms Brisotto said.

Government given incorrect information

The inquiry heard the state government was misled before it directed the lab in June to process all samples — regardless of how little DNA they contained.

It was given incorrect information about the process prior to the 2018 threshold changes, the inquiry heard.