Ariel Castro, the Cleveland, Ohio man who pled guilty to kidnapping and holding three woman captive for over 10 years, has reportedly killed himself.

Citing a statement given by Ohio corrections spokesperson JoEllen Smith, ABC News reports that Castro was found hanging in his cell at the Correctional Reception Center in Orient on Tuesday night (Sept. 3). Prison staff attempted to resuscitate Castro. He was pronounced dead later that evening at an area hospital.

Smith said that Castro was not on suicide watch, but was checked on every 30 minutes.

Castro pled guilty to 937 charges related to the abduction and rape of three Cleveland women -- Amanda Berry, Michelle Knight and Gina DeJesus. The women were kidnapped between 2002 and 2004. Castro was sentenced to life without parole, plus 1,000 years.