Convicted kidnapper Ariel Castro, 53, has been found dead in his prison cell at the Correctional Reception Center in Orient, Ohio.
Ohio Rehabilitation and Correction officials said Castro was found hanging in his cell around 9:20 p.m. local time.
Prison medical staff tried to revive him and transported him to The Ohio State University Wexner Medical Center where he was pronounced dead at 10:52 p.m. He was not part of the general prison population and was isolated from other inmates for his own protection.
On August 1 Castro was sentenced to life in prison plus 1,000 years for holding three women captive in a Cleveland home for more than a decade and raping them repeatedly. He pleaded guilty to 937 charges including aggravated murder, kidnapping, rape and assault. He was spared the death penalty after making a deal with prosecutors.
WATCH: Castro sentenced
Castro was watched closely in the Cuyahoga County Jail in the several weeks after his arrest and before his case was resolved by a guilty plea, with logs noting his activity every 10 minutes. He was taken off county jail suicide watch in early June after authorities determined he was not a suicide risk.
The three women, Amanda Berry, Gina DeJesus and Michelle Knight, disappeared separately between 2002 and 2004, when they were 14, 16 and 20 years old respectively. It was later revealed that each of the young women had accepted a ride from Castro.
Castro fathered a daughter with Berry, who is now six years old.
Knight said she became pregnant by Castro five times, but each time he starved and repeatedly punched her until she miscarried.
Their story was revealed on May 6, when Berry, 27, broke part of a door and yelled to neighbours for help. Castro was arrested later that evening.
WATCH: Timelapse of Cleveland house demolition:
This is the second high-profile suicide in an Ohio prison in a month.
On Aug. 4, death row inmate Billy Slagle was found hanged in his cell just days before his scheduled execution. He was condemned to death for fatally stabbing a neighbour.
–with files from The Associated Press