Can't say this is surprising, regardless of who made the final call.

Via Huffington Post:

According to JoEllen Smith of the Ohio Department of Corrections, Castro was found hanging in his prison cell at the Correctional Reception Center in Orient, Ohio, around 9:20 p.m. Tuesday. Although prison medical staff performed lifesaving measures, he was later pronounced dead at the Ohio State University Wexner Medical Center.

At the time of his death, Castro was isolated from other inmates for his own protection.