Minnesota Supreme Court reverses murder conviction in 1986 cold case killing

CHISHOLM, Minn. — Minnesota's highest court has reversed a northern Minnesota man's conviction in a brutal 1986 sexual assault and slaying.

In 2022, Michael Allan Carbo Jr. of Chisholm was found guiilty of first-degree murder while committing criminal sexual conduct in the killing of 38-year-old Nancy Daugherty, also of Chisholm. Carbo was sentenced to life in prison at the time.

On Wednesday, the Minnesota Supreme Court revered Carbo's conviction, saying the judge in Carbo's trial unjustly denied his defense's attempt to submit evidence of a possible alternative suspect.

"The district court abused its discretion by denying the defendant's motion to present alternative-perpetrator evidence because the defendant's proffered evidence clearly had an inherent tendency to connect the alternative perpetrator to the commission of the crime and could have been admitted under the ordinary rules of evidence, and the error was not harmless beyond a reasonable doubt," the Supreme Court wrote in its ruling.

Daugherty was found dead in her home on July 16, 1986, by police conducting a welfare check. Officials say she had been beaten, sexually assaulted and strangled. Witnesses later reported hearing a woman screaming in the early morning hours.

Carbo was arrested in connection in Daugherty's killing in 2020 after DNA analysis of public genealogy databases identified him as a suspect. A subsequent test showed Carbo's DNA matched the bodily fluids found on Daugherty and at the 1986 scene, authorities said.

Carbo's case will now revert to district court. The St. Louis County Attorney's Office, which originally charged Carbo, said it was "disappointed" in the decision and "remains committed to prosecuting Mr. Carbo."