A 45-year-old convicted murderer has died in state custody.

In a news release, the Missouri Department of Corrections announced the death of Mark Beel. Officials say Beel was pronounced dead on Friday, October 10, and 3:02am at the Western Missouri Correctional Center in Cameron.

Beel was serving an 18-year sentence for second-degree murder from St Louis County. He was received in the DOC on October 31 last year.

Prison officials say Beel died of apparent natural causes.