Colorado Bureau of Investigation finds DNA scientist manipulated data in hundreds of cases over decades

A now-former forensic scientist with the Colorado Bureau of Investigation (CBI) manipulated or omitted DNA test results in hundreds of cases, an internal affairs investigation found, which prompted a full review of her work during her nearly 30-year career at the agency.

The CBI released the findings of the investigation into Yvonne “Missy” Woods Friday, which concluded Woods’ handling of DNA testing data affected 652 cases between 2008 and 2023, including posting incomplete results in some cases. A review of her work from 1994 to 2008 is also underway, according to the CBI.

“This discovery puts all of her work in question, and CBI is in the process of reviewing all her previous work for data manipulation to ensure the integrity of all CBI laboratory results,” the agency said. “CBI brought in third-party investigative resources to protect the integrity of the inquiry.”

Woods, a 29-year veteran of the agency’s crime lab, was placed on administrative leave in October after the CBI became aware DNA sample testing performed by Woods “may have deviated from standard operating procedures,” the agency said. She didn’t perform any laboratory work thereafter and retired on November 6, it said.

A separate criminal investigation into Woods’ conduct is ongoing, and the CBI said it continues to work with law enforcement agencies across the state.

Colorado Attorney General Phil Weiser declined to comment on the criminal case against Woods when contacted by CNN on Friday.

The CBI internal investigation, which was conducted in collaboration with the Kansas Bureau of Investigation, did not find Woods falsified DNA matches or fabricated data. It revealed Woods had omitted material facts in official criminal justice records, thus tampering with DNA testing results, and violating agency policies ranging from data retention to quality control measures, the agency said.

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

Analyst trained ‘generations’ of scientists, attorney says

In a statement to CNN on Friday, Woods’ attorney Ryan Brackley said the findings support Woods’ earlier statements that “she’s never created or reported any false inculpatory DNA matches or exclusions, nor has she testified falsely in any hearing or trial resulting in a false conviction or unjust imprisonment.”

Brackley said his client has been a “loyal and dedicated forensic scientist” during her time at the agency and has worked with and trained “generations” of prosecutors, scientists and law enforcement agents.

The agency said its forensics team discovered Woods deleted and altered data that served to conceal evidence of her tampering as well as her failure to “troubleshoot issues within the testing process.” The agency said Woods’ manipulations “appear to have been the result of intentional conduct.”

The CBI said it’s also conducting a “comprehensive audit” of all DNA analysts to “ensure the accuracy and completeness of its entire catalog of records.” As part of this process, the agency said it discovered a separate case in which an analyst with the Weld County Sheriff’s Office at the Northern Colorado Regional Forensic Laboratory may have also manipulated testing data.

The sheriff’s office announced last month it fired the DNA analyst as the result of an internal investigation

Boulder District Attorney Michael Dougherty told CNN in a statement his office has identified 15 open cases and 55 closed cases in which Woods has testified as a witness.

“For the past several months, prosecutors around the state have waited anxiously for information because of the impact on victims, the accused, and our ability to do justice,” Dougherty said.

The district attorney’s office did not have information on how many of its cases were affected by Woods’ conduct and emphasized it is too early to know whether any cases will need to be re-tried.

The office of Colorado’s Fourth Judicial District Attorney told CNN that CBI had informed them of 75 potentially affected cases within its jurisdiction, adding Woods was not used as an expert witness in any of those cases.

Woods’ faulty analysis led to wrongful conviction, lawsuit claims

A week after Woods resigned from CBI, attorney Mark Burton filed a federal lawsuit on behalf of his client, 64-year-old James Hunter, who is currently in prison. The lawsuit identifies Woods as the lead scientist on his case and alleges Hunter was prosecuted and tried based on fabricated and false evidence.

The suit claims Hunter was wrongly convicted of the 2002 burglary and sexual assault of a mother and her daughter by a suspect who was wearing a mask.

Woods conducted an early, microscopic examination of hairs collected from the crime scene, which was used as evidence to link Hunter to the crime, the lawsuit says. A preliminary hearing dismissed the charges against him after a separate examination found the hairs belonged to the victim, the suit says.

In acknowledging her error in the examination, Woods told the court it was a “blow to her ego,” according to the lawsuit.

But 10 months after the crime, new evidence of a hair was introduced into the case as evidence, and used to indict Hunter for the same crimes, according to the lawsuit.

“There is no verification or record of collection of this hair from the crime scene by the Crime Scene Investigation Unit,” the suit noted.

Hunter was ultimately convicted on the charges based on the hair evidence, which was examined and tested by Woods, the lawsuit says.

Last month, attorneys for Woods filed a motion to dismiss Hunter’s complaint.

The Jefferson County District Attorney’s office told CNN due to the active criminal investigation into Woods’ conduct, which includes labs in its jurisdiction, it is unable to comment.

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