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Investigation finds Colorado DNA analyst intentionally manipulated data

The investigation found 652 cases in which a DNA analyst who worked for the Colorado Bureau of Investigation manipulated data.

A Colorado Bureau of Investigation DNA analyst intentionally manipulated data in the testing process for at least 15 years, according to an internal affairs investigation.

Yvonne “Missy” Woods, a now-former DNA scientist who worked at the CBI crime lab for 29 years, has been under investigation since September 2023, according to the bureau, known as CBI.

The investigation concluded that Woods manipulated data in the DNA testing process and in some cases posted incomplete test results.

“At this time, 652 cases have been identified as affected by Woods’ data manipulation between 2008 and 2023,” the CBI said in a release. “A review of Woods’ work from 1994 to 2008 is also underway.”

internal affairs probe dna lab tampering
CBI Headquarters in Lakewood, Colo.Google Maps

The investigation, dated Feb. 26, found Woods "Omitted material facts in official criminal justice records," "Tampered with DNA testing results by omitting some of those results," and violated the bureau's code of conduct and lab policies "ranging from data retention to quality control measures."

According to the investigation, a DNA forensics team found Woods manipulated her work by deleting and changing data that hid the fact that she interfered with controls and failed to troubleshoot problems that arose during the testing process. It also found she did not provide adequate documentation in case records related to tests she performed.

"These manipulations appear to have been the result of intentional conduct on the part of Woods," the CBI said.

The CBI said the findings “puts all of her work in question."

Ryan Brackley, an attorney representing Woods, said she "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."

The bureau launched the investigation in September after becoming aware that a DNA sample testing performed by Woods "may have deviated from standard operating procedures."

Woods was placed on administrative leave on Oct. 3, and later retired from her post on Nov. 6. The CBI said she did not perform any additional lab work during that time.

Since Oct. 3, the CBI, in collaboration with members of the Kansas Bureau of Investigation, looked into all of Woods' work over the course of her 29-year career with the bureau.

Ultimately, the review did not find that Wood "falsified DNA matches or otherwise fabricated DNA profiles."

"She instead deviated from standard testing protocols and cut corners, calling into question the reliability of the testing she conducted," CBI said, adding that Woods "should have conducted additional testing to ensure the reliability of her results in these affected cases."

Her attorney said the investigation's findings "support Ms. Woods earlier statements 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."

A separate criminal investigation into Woods launched late last year is still underway, according to the CBI.

The CBI said it is working to implement changes that will "enhance the integrity of its testing processes and their results" and to prevent this kind of issue from arising in the future.

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

The bureau said it is also working through an audit of all of its DNA analysts "to ensure the accuracy and completeness of its entire catalog of records."

Over the course of the audit, the CBI found that an additional analyst who works for the Weld County Sheriff’s Office at the Northern Colorado Regional Forensic Laboratory may have also manipulated DNA testing data, but noted that this case is separate from Woods'.

That analyst, Chiara Wuensch, was fired by the Weld County Sheriff’s Office last month after an internal investigation that centered on “anomalies” in her work. The investigation, which began Jan. 31, found she “violated the Weld County Code for expectations of proper conduct, and the sheriff’s office standards of conduct policy for not cooperating with the agency’s internal investigation,” according to the sheriff’s office.

Wuensch did not immediately respond to a request for comment on her termination or the circumstances surrounding it.

The sheriff's office said it intends to pursue criminal charges against Weunsch.