(NEWSER) – Ariel Castro has been found dead in his prison cell just 35 days into his life-plus-1,000-years sentence for keeping three women captive in his home for a decade. The 53-year-old hanged himself, say officials at the Correctional Reception Center in Orient, Ohio. Prison officials found his body about 9:20pm. They tried emergency life-saving measures, but he was pronounced dead at a hospital. Officials say Castro was in protective custody, meaning he was in a cell by himself and was checked every 30 minutes, but he was not on suicide watch, the APreports.

Prison officials say a full investigation of the apparent suicide is under way, the Cleveland Plain Dealer reports. Castro had no hope of ever leaving prison after pleading guilty to more than 900 counts including rape and kidnapping. Michelle Knight, the woman he seized first, was the only victim to speak at his sentencing. "I spent 11 years in hell, and now your hell is just beginning," she said. "I will overcome all this that has happened, but you will face hell for eternity."

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