HELENA, Mont. (AP) — Montana State Prison officials say an inmate has died of an apparent hanging in an out-of-state prison.

Prison spokeswoman Linda Moodry says 38-year-old Timothy DeHerrera was found unresponsive in his cell late Saturday afternoon. He was hanging with a sheet that was tied to a cell window.

He was pronounced dead at 6:30 p.m.

DeHerrera's death is under investigation.

DeHerrera was first sentenced to prison in April 2004 for two auto thefts and assault on a peace officer in Yellowstone County. He was sentenced in September 2008 for riot and criminal mischief.

Moody declined to say where DeHerrera had been held, saying his move was part of an interstate transfer of inmates.