Former Weld sheriff's DNA analyst won't face charges in Weld over case processing anomalies – Greeley Tribune

The machines used to test DNA are located in a closed room to ensure no contamination will occur at the Northern Colorado Forensic Laboratory in Greeley. (Jim Rydbom/Staff Photographer)

A former DNA analyst with the Weld County Sheriff's Office will not face any charges in Weld County for discrepancies found in her case file, the Weld County District Attorney's Office announced Thursday morning.

The prosecutor's office determined there was no probable cause to believe Chiara Wuensch — who spent more than 10 years at the Northern Colorado Regional Forensic Laboratory — committed a crime in her analysis, according to a Press release.

“After a complete review of all the evidence and circumstances, it is clear that the anomalies found in Ms. Wuensch’s work do not meet the legal threshold for criminal charges,” Weld County Prosecutor Michael Rourke said in the press release. “The evidence does not support a finding of criminal intent and, therefore, it would be inappropriate to press charges in this matter. »

To prove a criminal charge, the prosecutor's office said the prosecution must not only prove the criminal act but also the criminal intent behind that act.

Investigators say a review of Wuensch's work revealed only five anomalies among thousands of DNA data entries. The anomalies fall into three categories, according to the press release:

• Alleged deletion of data indicating a small amount of male DNA.

• Allegedly adding the word “undetermined” to a cell in a spreadsheet.

• Alleged alteration of values ​​linked to potential contamination at smaller numbers.

The prosecutor's office said the anomalies could be considered intentional acts to avoid the extra work required by CBI standard operating procedures, but Wuensch denied intentionally changing or deleting the data, instead attributing the discrepancies to an error of the user when entering information in Microsoft Excel.

Wuensch said there was no reason for her to intentionally alter the data because she was still performing the DNA amplification required by those standard operating procedures, according to the affidavit. The CBI investigation corroborated his account and confirmed that the anomalies had no impact on the identification or elimination of DNA in criminal cases.

DNA amplification is a process that copies a specific segment of DNA without increasing adjacent segments, resulting in larger samples for profiling and reducing analysis time.

Wuensch arrived at the Northern Colorado Regional Forensic Lab – which provides forensic services to sheriff's offices in Weld and Larimer counties, as well as police in Greeley, Loveland and Fort Collins – in November 2013, from the Wisconsin State Crime Lab, where she was a senior forensic pathologist. scientist for DNA analysis. She had more than 23 years of experience at the Wisconsin lab, according to her LinkedIn page.

The sheriff's office began investigating Wuensch on Jan. 31, the department announced in February. The agency said the investigation found she violated the Weld County Code of Expectations of Good Conduct and the Sheriff's Office Standards of Conduct Policy for failing to cooperate with the investigation internal to the sheriff's office.

The anomalies in Wuensch's case first came to light through a separate, active investigation by the Colorado Bureau of Investigation into its own personnel, the sheriff's department said.

Authorities discovered anomalies in Yvonne “Missy” Woods' DNA testing work in 2023, opening internal and criminal investigations. Woods had been with the CBI for 29 years, leaving before the agency publicly announced the anomalies in November.

Woods was found to have cut corners on much of his DNA testing, then covered up his shortcuts by changing, deleting or omitting data in his lab work, according to the CBI.

Woods admitted to investigators in November that she suppressed data on low amounts of male DNA in sexual assault cases so as not to have to conduct additional testing that she said would not produce conclusive results , according to the internal report.

Although she admitted cutting corners, Woods insists she never gave false testimony in court. She also claims her work has never led to false convictions or imprisonments, according to a statement from her lawyer earlier this month.

The CBI found problems in 654 of Woods' cases between 2008 and 2023. As of last week, the Bureau was still reviewing his cases between 1994 and 2008.