COLUMBUS (AP) -- Columbus police are reviewing about 3,000 DNA test results, the department announced Wednesday, saying updated reporting procedures weren't always followed.
Some reports given to investigators, prosecutors, defense attorneys and courts lacked a statistical weighting system in the reports' analyses, said Police Chief Kim Jacobs.
Jacobs said she learned of the situation last week involving DNA test results from mid-2009 through last September.
At issue are best practice standards for dealing with DNA evidence. Those standards were introduced in 2009 but not always followed, Jacobs said.
"The expectations to follow best practices and proper procedures extend to all of our operations and where those procedures impact criminal cases and the prosecution of our citizens, there is no room for mistakes," she said.
Jacobs says closed criminal cases could be affected but the number should be low.
That's because not all DNA tests relate to a suspect -- some could belong to a victim or witness, she said. In addition, other factors could have led to a prosecution, including witnesses, confessions, fingerprints or surveillance video.
Jacobs says an internal review and external audit uncovered the problem. She says the city is hiring an independent DNA expert to audit the crime lab's DNA procedures.
The department notified local, state and federal prosecutors and investigators.
The statistical weight of a DNA result -- the odds that the sample is a direct match to a suspect -- is the hallmark of the strength of evidence, said Columbus defense attorney Adam Nemann.
"Sometimes that's the only evidence that puts an individual at a crime scene," said Nemann, who plans to review several of his cases where individuals were imprisoned based on DNA results while professing their innocence.
"Every attorney that has dealt with a case utilizing the Columbus crime lab has to go back and check to make sure their clients are not wrongly incarcerated," Nemann said.
Andrew Welsh-Huggins can be reached on Twitter at https://twitter.com/awhcolumbus.