Minneapolis News

Hennepin County crime lab resumes DNA testing after finding source of contamination

The Hennepin County Sheriff’s Office announced Thursday that it has resumed DNA testing at its crime lab.

That’s after the lab’s forensic scientists tracked down the cause of “sporadic DNA contamination” which had forced a suspension of testing this fall.

Officials now say a plastic plate supplied by a third-party vendor was the source of an unknown DNA profile that showed up in a control sample at the Hennepin County lab, and was also found in other labs around the country.

“It was our experts who made the identification and notifications,” the sheriff’s office said in a news release. “This is a testament to their commitment to science and dedication to the forensic science profession.”

The lab is now using a different kind of plastic plate in its work. Scientists also reviewed more than 50,000 samples from previous cases — identifying fewer than 10 that might need retesting. As of Thursday, officials said the lab has not received any requests for retesting.

The sheriff’s office had said in October, when it put DNA testing on hold, that “because the contamination is due to an unknown DNA profile, no criminal charges or convictions could have resulted from this contamination.”