Man killed by police in Fort Collins is linked to unsolved murder case

FORT COLLINS, Colorado – A man shot and killed by Fort Collins police last month is the suspect in an unsolved 2019 murder case, according to Fort Collins police.

The incident began at approximately 12:41 p.m. on July 21, when police were called to a single-vehicle rollover crash at the corner of Mountain and Bryan Avenues. According to Fort Collins police, a sergeant and patrol officer found the driver outside the vehicle and armed with a firearm.

Police said the man fired at officers, hitting one of them, “during their brief encounter,” and then ran into the nearby Grandview Cemetery.

Additional police officers arrived and surrounded the cemetery. Officers found the man and “additional gunfire occurred” before the man fell to the ground, police said. Officers used the department's armored rescue vehicle to approach the injured man. He was then taken to the hospital, where he succumbed to his injuries.

The Larimer County Coroner identified the man as Clayton Pierce, 42, of Fort Collins.

The injured officer was treated at the hospital for a gunshot wound and released.

After an investigation, the 8th Judicial District Attorney's Office concluded that the officers' use of deadly force was justified and that no charges would be filed against them.

Investigators also determined that Pierce was a suspect in a recently reopened unsolved murder case from 2019.

According to Fort Collins police, officers responded to reports of a man lying unconscious in his home in 2019. The man – later identified as Joseph “Sonny” Brigman – had been the victim of a homicide.

The department said investigators had “exhausted all investigative avenues at this time,” but the case had stalled. Investigators reopened the investigation in 2023 “in hopes of finding new leads and further examining evidence.” The investigation eventually led them to Pierce as a suspect.

According to Fort Collins police, investigators concluded that “there was sufficient evidence to prove that Pierce was responsible for Brigman's death.”

According to Fort Collins police, the Larimer County District Attorney's Office filed charges against Pierce on August 20. Prosecutors said they would have filed premeditated murder charges if Pierce were not dead.