PORTLAND, Ore. (KOIN) — A 20-year-old Castle Rock man faces 1st-degree murder charges in the death of a man whose body was found in the Coweeman River.

Jeremy B. Leiniger was arrested late Friday by detectives with the Cowlitz and Thurston county sheriff’s offices, authorities said in a release.

The body of Clark Calquhoun was recovered on January 28 in Kelso. The 53-year-old had been reported missing on January 6, but the Rainier, Washington resident was last seen December 28. An autopsy revealed he was shot to death. Authorities did not say how many times he was shot or how long he’d been dead.

Leiniger was booked into the Thurston County jail. Investigators have not revealed the motive, where the crime happened or if other people may be arrested.

KOIN 6 News will continue to follow this story.