Prison consultants have concluded that Cleveland kidnapper Ariel Castro committed suicide in his prison cell and that his death was not the accidental result of auto-erotic asphyxiation, The Associated Press reported.

Released Tuesday, the consultants' report says the evidence points to suicide, according to the AP.

Castro, 52, was found hanged with a bedsheet Sept. 3, coroner Dr. Jan Gorniak said. He was being held at the Correctional Reception Center in Orient.

Prison medical staff tried to revive him.

Castro pleaded guilty in August to 937 counts, including the kidnapping of Michelle Knight, Georgina DeJesus and Amanda Berry. He was sentenced to life plus 1,000 years.