Ariel Castro, sentenced to life in prison for the kidnapping, rape and beatings of three Cleveland women he held captive for years in his house, was found hanged in his Ohio prison cell late on Tuesday, a state corrections official said.
The former school bus driver, who was under protective custody and isolated from other inmates at the Correctional Reception Center in Orient, was found dead at about 9:20 p.m. when prison staff were making their rounds, Rehabilitation and Correction Department spokeswoman JoEllen Smith said.
After prison medical personnel tried to resuscitate him, Castro, 53, was transferred to an area hospital and pronounced dead about 90 minutes later, she said.
Castro was sentenced on August 1 to life plus 1,000 years in prison without the possibility of parole for abducting his three victims and keeping them imprisoned in the dungeon-like confines of his house, where they were starved, beaten and sexually assaulted for about a decade.
He was taken into custody just after the three women he held captive - Amanda Berry, 27, Gina DeJesus, 23, and Michelle Knight, 32 - were freed from the house with assistance from neighbors who heard Berry's cries for help and came to her aid.
Rescued along with them was Berry's 6-year-old daughter, fathered by Castro and born during her mother's captivity.
Capping one of the most sensational U.S. crime stories in recent memory, Americans were elated by news that the three women had been found alive and freed but were stunned by the circumstances of their ordeal.
Castro pleaded guilty in July to a total of 937 offenses, including kidnapping, rape, felonious assault and a charge of aggravated murder under a fetal homicide law for the forcible miscarriage of one of his three victims.
His plea deal with prosecutors spared Castro a possible death penalty for murder.
Castro had been incarcerated since August 5 at the Correctional Reception Center, a prison processing facility outside Columbus, the state capital, about 150 miles southeast of Cleveland.
He was to remain there while undergoing a series of mental and physical evaluations before being transferred to a more permanent lockup, prison officials said.
"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 added.
Cuyahoga County prosecutor Tim McGinty acknowledged after Castro's sentencing that a suicide note and confession written by Castro was found by authorities at his residence when they searched his home following his arrest in May.
But McGinty dismissed the letter as an attempt of Castro, whom he described as a "narcissist", to feel sorry for himself and to place blame on his victims.
The house where the three women were held, bound with chains and ropes for periods of time, has since been torn down along with two homes on adjacent lots.
A longtime bus driver for Cleveland public schools until he was fired in 2012 after a series of disciplinary actions against him, Castro had kidnapped each of his victims by luring them into his car with offers of a ride.
The three vanished without a trace between 2002 and 2004 - two of them as teenagers - and were rescued on May 6, 11 years after the first of them disappeared.
At his sentencing, Castro apologized for his actions but also sought to blame his behavior on a sexual obsession and his own history of being abused as a child, declaring: "I am not a monster."
Confronting Castro in court during that proceeding, Knight told him: "I spent 11 years of hell. Now your hell is just beginning."