Colorado finds DNA scientist cut corners, raising questions in hundreds of criminal cases

A former Colorado Bureau of Investigation DNA scientist intentionally cut corners and didn’t follow standard testing protocols, raising questions about hundreds of cases in which she processed evidence, the agency said Friday, calling it “an unprecedented breach of trust.”

The investigation found Yvonne “Missy” Woods manipulated data in the DNA testing process and posted incomplete test results in some cases, but it did not find that she falsified DNA matches or otherwise fabricated DNA profiles, the bureau said.

“The discovery puts all of her work in question," the agency said in a statement, adding that it was reviewing “all her previous work for data manipulation to ensure the integrity of all CBI laboratory results.”

Investigators have found 652 cases affected by Woods' data manipulation from 2008 through 2023, the agency said. They're still reviewing additional work dating back to 1994.

Woods worked for the lab for 29 years. CBI became aware of irregularities in her work in September 2023. She was placed on administrative leave in early October and retired on Nov. 6, the agency said.

The Colorado Department of Public Safety in January asked the legislature for $7.5 million to pay for an independent lab to retest up to 3,000 DNA samples and for district attorneys to review and potentially reprosecute cases that are affected by lab errors.

A criminal investigation of Woods is also underway, officials said.

“Public trust in our institutions is critical to the fulfillment of our mission,” CBI Director Chris Schaefer said in a statement. “Our actions in rectifying this unprecedented breach of trust will be thorough and transparent.”

While the investigation found Woods deviated from standard protocols, "she has long maintained that she's never created or falsely reported any inculpatory DNA matches or exclusions, nor has she testified falsely in any hearing or trial resulting in a false conviction or unjust imprisonment,” her attorney, Ryan Brackley, said in a statement to The Associated Press on Friday.

“To the extent that the findings of the internal investigation will call her good work into question, Ms. Woods will continue to cooperate to preserve the integrity of her work that resulted in true and just criminal justice findings," Brackley said.

The Colorado Bureau of Investigation said Woods should have conducted additional testing to ensure the reliability of her results, as is required under its lab policies.

Investigators found Woods deleted and altered data to conceal her tampering with controls, deleted data that showed she failed to troubleshoot issues within the testing process and that she did not provide thorough documentation of certain tests performed in case records.

In the course of the investigation, CBI found indications that a DNA analyst who had been working for the Weld County Sheriff's Office at the Northern Colorado Regional Forensic Laboratory in Greeley, Colorado, for about 10 years may have also manipulated DNA testing data. The analyst was fired on Feb. 28, and the county intends to seek criminal charges, the sheriff's office announced on March 1.