SEATTLE -

A Washington state inmate may have been dead in his cell for more than 37 hours.

An incident summary obtained by The Associated Press shows that there's no evidence that Jerry Levain Jamison moved around his cell at Monroe Correctional Complex after the night of Sept. 19. The next day, an officer placed mail on Jamison's legs, and staff members reported conducting regular inmate counts.

It wasn't until the middle of the day on Sept. 21 that officials found Jamison was actually dead, his body cold and rigid.

Robert Herzog is superintendent of Monroe Correctional Complex. He says officers who conducted checks assumed that Jamison was asleep.

The incident review identified times when video documentation didn't support officer accounts that a "tier check" had occurred. Herzog says officials will be investigating staff conduct.