An autopsy has confirmed that Ariel Castro, who was sentenced to life in prison for holding three women captive for a decade in Ohio, committed suicide Tuesday by hanging himself with a bedsheet.
The former school-bus driver, who pleaded guilty in July and was convicted of kidnapping and sexual abuse, was found to have hanged himself in his cell at 9:20 p.m. local time.
Castro, 53, who was under protective custody in isolation from other inmates at the Correctional Reception Center in Orient, Ohio, was found by prison staff during their rounds at the facility, said JoEllen Smith, Ohio Department of Rehabilitation and Correction spokeswoman.
Smith said that inmates in protective custody are checked at least every 30 minutes.
"Upon finding inmate Castro, prison medical staff began performing life-saving measures," she said.
"Shortly after, he was transported to OSUMC (Ohio State University Wexner Medical Center), where he was pronounced dead at 10:52 p.m.
"A thorough review of this incident is under way, and more information can be provided as it becomes available pending the status of the investigation," Smith said.
Castro was sentenced to life in prison without parole, plus 1,000 years, on Aug. 1 for holding Michelle Knight, Gina DeJesus and Amanda Berry captive in his home on Cleveland's west side.
He avoided the death penalty by pleading guilty to 937 charges, including aggravated murder for causing Knight to miscarry by beating and starving her.
Knight, now 32; Berry, 27; and DeJesus, 23, went missing from the west side of Cleveland between 2002 and 2004.
They were rescued on May 6, along with Berry's 6-year-old-daughter by Castro, after neighbors heard Berry's cries and helped her break through her front door.
"I served 11 years of hell. Now your hell is just beginning," Knight said of Castro in a statement read to the court at his sentencing.
Knight was abducted when she was 20, Berry was 16 when she disappeared a few blocks from her home, and DeJesus was 14 when she disappeared while walking home from school on April 2, 2004.
Police said the women had been held in separate rooms, but had known of the presence of the other women in the house.
Al Jazeera and wire services