Convicted murderer accused of killing inmate at Jefferson City prison

COLUMBIA, Mo. (KMIZ)

A convicted murderer has been accused of killing an inmate at Jefferson City Correctional Center.

Zachariah Peterson, 38, was charged with second-degree murder and causing violence to an inmate after a grand jury indictment was filed on Tuesday. A no-bond warrant was issued.

Details were scant because of the lack of a probable cause statement, but Cole County Prosecutor Locke Thompson confirmed the victim was Joshua McNair, 44.

A May 6 press release from the Department of Corrections says McNair was pronounced dead at 2:19 p.m. Saturday, May 2. McNair was serving a seven-year sentence for first-degree assault from Lawrence County, the release says. McNair was received by the DOC on Oct. 31, 2025.

The complaint in the murder case says “defendant knowingly caused the death of Confidential Victim by striking him" on May 2.

Peterson is currently serving a 30-year sentence after a Boone County jury found him guilty of second-degree murder on March 6, 2012. He is still being held at Jefferson City Correctional Center.