A judge overturns conviction in 1994 Boulder murder case due to flawed DNA testing
A judge overturned the conviction in a 1994 Boulder murder case Friday because of flawed DNA testing by disgraced Colorado Bureau of Investigation scientist Yvonne “Missy” Woods.
It’s the first case to be thrown out since the CBI beginning in 2023 discovered hundreds of criminal investigations in which Woods cut corners in her DNA testing — a scandal that has cost Colorado millions of dollars already and shaken the state’s criminal justice system.
Boulder District Court Judge Nancy Woodruff Salomone vacated the first-degree murder conviction of 49-year-old Michael Clark, who has been serving a sentence of life without parole since being convicted in 2012 in the cold-case shooting death of Boulder city employee Marty Grisham.
A hearing is scheduled for June 6 at which Boulder County District Attorney Michael Dougherty is expected to announce whether or not he will retry Clark on charges stemming from the 1994 killing.
“This is a really good day,” said Adam Frank, Clark’s attorney. “Michael Clark’s conviction is gone.”
Dougherty had filed a motion late Friday afternoon asking the judge to vacate Clark’s conviction because Woods’ interpretation of the DNA testing in the Grisham case is now in question after an independent lab retested crime scene evidence.
“Based on those results, as well as the significant claims of juror misconduct and ineffective assistance of counsel, our office determined that the conviction must be vacated,” Doughtery said in a statement. “It is the right thing to do, after considering all three issues. In light of the charges in this case, we will carefully and thoroughly analyze all the evidence to determine the right and just outcome.”
The juror misconduct claim involved the discovery that one of the jurors ignored the judge’s instructions and visited the crime scene during the trial, according to the DA’s motion.

Clark was always a suspect in the 1994, killing but investigators only had circumstantial evidence at the time. It was Woods’ DNA testing of a Carmex lip balm container found at the scene that led investigators to finally charge Clark in the cold case in 2012.
Doughtery’s motion to vacate said an independent lab retested Woods’ original analysis and created a new sample from the Carmex container. It was testing of that new sample that found new results that could statistically exclude Clark.
“There could be a number of reasons for these results, including the advances in DNA technology,” the DA’s motion stated. “Regardless of the reason, this is new evidence.”
Grisham, who worked as the city of Boulder’s information services director, was shot four times on the night of Nov. 1, 1994, after he answered a knock at his apartment door. The killer fled before Grisham’s girlfriend could see him.
The killing was a cold case for nearly two decades before Boulder police reopened it in 2009. In 2011, Woods took DNA samples from the Carmex container and determined they excluded 99.4% of the world’s male population, but could include Clark.
Clark was charged with first-degree murder and convicted by a jury in 2012.
He already had brought up the DNA testing in an appeal of his murder conviction, saying his defense lawyer never hired another DNA expert to challenge Woods’ conclusions.
Then the CBI discovered in 2023 that Woods had mishandled hundreds of DNA samples and covered up her shortcuts by altering, deleting or omitting data from lab work — skipping protocols that are in place to ensure accurate results.
Woods was charged with 102 felonies in January. That case is pending.
Her shoddy work has rattled Colorado’s justice system. While Clark becomes the first person to successfully challenge a conviction, others are expected to follow.
The CBI estimates Woods’ misconduct has already cost the agency more than $11 million, a figure that includes state funds allocated to pay for re-testing and compensate district attorneys’ offices across Colorado to address wrongful-conviction claims tied to Woods’ work.
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