A former forensic scientist intentionally manipulated DNA evidence during her 29-year career at the Colorado Bureau of Investigation, casting doubt on at least 652 criminal cases she handled, including some of the most high-profile trials, according to investigation findings released by the agency Friday.
That number could grow as outside investigators continue to review DNA testing done by Yvonne “Missy” Woods, after a probe revealed she manipulated data in the testing process and in some cases, posted incomplete test results, in the cases she handled between 2008 and 2023.
The discovery is putting all of Woods’ work into question and CBI is also looking at her work dating to 1994, when she started working for CBI. The agency launched the investigation in September after anomalies were discovered in her work.
“Public trust in our institutions is critical to the fulfillment of our mission,” CBI Director Chris Schaefer said in announcing the results of the investigation. “Our actions in rectifying this unprecedented breach of trust will be thorough and transparent.”
The investigation found that Woods did not falsify DNA matches or fabricate DNA profiles. Rather, the report said she deleted and altered data in case records, tampered with DNA testing results and deviated from standard testing protocols and cut corners.
Her lawyer, Ryan Brackley, said Woods never created or reported false DNA evidence intending to incriminate or gave false testimony in a hearing or trial that resulted in a false conviction.
“To the extent that the findings of the internal investigation calls into questions the rest of her work over 29 years with the Colorado Bureau of Investigation, Woods will continue to cooperate with law enforcement to preserve the integrity of her work that resulted in true and just criminal justice findings — whether arrests, convictions or exonerations,” Brackley said in a statement Friday.
The announcement of the investigation set off a scramble in district attorney’s offices across the state to review the affected cases for problems. Prosecutors worry that more than 1,000 criminal convictions could have relied on dubious evidence due to anomalies in Woods’ work.
In a statement Friday, the Office of the Colorado State Public Defender said criminal cases would likely have to be re-opened, but declined to provide specific details or identify cases that Woods’ misconduct may have affected.
Lawyers with the state’s public defender office represent defendants in 70% of all criminal cases and up to 80% of those charged with serious crimes.
The office said it learned of Woods’ misconduct in a press release issued by CBI on Friday and called the agency’s lack of transparency “extremely concerning.”
“One of the most pressing questions is whether any person has been wrongfully convicted as a result of misconduct,” an unsigned statement from the office said. “CBI and other law enforcement should be immediately forthcoming with the public and the people directly impacted by the misconduct and possible crimes committed by the DNA analysts they employed.”
Officials previously said they would need to retest and review 3,000 DNA samples at a cost of $1,000 each. That’s almost as many tests as the 3,600 the state typically conducts in an entire year.
The review came with a hefty price tag for the state. The Joint Budget Committee earlier this year approved a $7.5 million addition to the CBI budget to cover the expense of re-testing DNA samples and reviewing convictions that relied on evidence that is now in question.
A separate criminal investigation into Woods, also initiated late last year, is underway, CBI said. The agency is also conducting an audit to review all DNA analysts “to ensure the accuracy and completeness of its entire catalog of records,” it said Friday.
While investigating Woods, CBI found that an analyst employed by the Weld County Sheriff’s Office at the Northern Regional Forensic Laboratory may have also manipulated DNA testing data, the agency said. The case is separate from Woods’ case.