Crime lab analyst altered DNA evidence in hundreds of cases, prosecutors say

A former lab scientist at the Colorado Bureau of Investigation faces felony charges after she falsified DNA tests in hundreds of cases and sent fraudulent reports to 24 law enforcement agencies across the state, prosecutors announced Wednesday.

Yvonne “Missy” Woods, 64, who worked for the bureau from 1994 to 2023, omitted signs of contamination introduced during the DNA testing process and incorrectly reported that some samples did not contain male DNA in analyses performed for cases including murder and sexual assault, according to an affidavit filed in Jefferson County Court. Questioned by investigators, Woods allegedly said she falsified results to move cases along quickly and avoid additional work.

Woods, who retired in 2023 after the bureau began investigating her work, tampered with test data in at least 654 cases, the Colorado Bureau of Investigation announced in June. The revelation rattled Colorado’s courts, where attorneys are still grappling with the immense demands of retesting DNA samples and scrutinizing old cases. Woods’ misconduct could cost the bureau around $11 million, District Attorney Alexis King said in a Wednesday statement.

Woods was charged Tuesday with cybercrime, perjury, 48 counts of attempting to influence a public servant and 52 counts of forgery.

Lindsay Brown, an attorney for Woods, declined to comment.

Before allegations of misconduct surfaced, Woods was a respected leader in the Colorado Bureau of Investigations lab known as a fast worker who spent weekends on the job and regularly maxed out her overtime, the Denver Post reported.

The Colorado Bureau of Investigation began investigating Woods in 2023 after an intern there working on a research project discovered missing data in test records entered by Woods, according to the affidavit.

Investigators subsequently found a slew of test results in Woods’ records containing manipulated data, the affidavit states. Woods allegedly changed or removed test results that indicated a DNA sample may have been contaminated, which would have required her to redo tests. Woods also allegedly deleted test results in sexual assault cases indicating male DNA was present, reporting instead that no male DNA was found in samples.

Colleagues had raised concerns about Woods’ work in 2014 and 2018, the affidavit states. Woods was briefly placed on administrative leave in 2018 after a colleague found evidence of contamination in a DNA test Woods performed, according to the affidavit and the Colorado Bureau of Investigation’s report. Despite this, she was not fired and returned to her work. The affidavit does not explain why Woods was not disciplined at the time.

Investigators questioned Woods in April about anomalies in her test results, according to the affidavit. Woods said that she manipulated data in 2018 because she was in a hurry, and said that in other cases she also manipulated data to avoid troubleshooting problems and quickly move cases forward, according to the affidavit.

Woods’ fraudulent test results compromised hundreds of cases, including over 30 sexual assault cases, according to prosecutors.

The Colorado Bureau of Investigation’s report on her alleged misconduct, which was released in June, sent shock waves across the state’s legal system. Public defenders said they would need millions of dollars to pursue wrongful conviction claims in response, the Denver Post reported.

A man convicted of a 1994 murder in Boulder challenged his conviction in August, and prosecutors said they offered a triple murderer a plea deal and a lighter sentence in June due to issues with evidence Woods had tested, according to the Denver Post.

Woods turned herself in upon being charged and made her first court appearance virtually from jail on Thursday, the Denver Post reported.