Ariel Castro, who was convicted last month on charges related to the capture and imprisonment of three women in Cleveland, has been found hanged in his prison cell, the Ohio Department of Rehabilitation and Correction said in an email.

Castro, 53, was in a cell by himself in protective custody at the Correction Reception Center in Orient, Ohio, wrote JoEllen Smith with the state corrections agency. Castro was found at 9:20 p.m. ET in the cell, where checks are required every 30 minutes, Smith wrote in the email.

After prison medical staff attempted lifesaving measures, Castro was transported to The Ohio State University Wexner Medical Center and pronounced dead at 10:52 p.m. ET, Smith wrote