When Ariel Castro agreed to plead guilty to murder and kidnapping -- charges that would theoretically keep him in jail for more than a thousand years -- he won one concession. His life.

On Tuesday, just five weeks into his sentence, the 53-year-old Cleveland kidnapper committed suicide, begging the final question in the bizarre case -- why?

Castro was found hanging in his prison cell at the Correctional Reception Center in Orient, Ohio, around 9:20 p.m. Tuesday. Emergency medical technicians were called to resuscitate him. An hour and a half later, he was pronounced dead at the Ohio State University Wexner Medical Center.

In May, Castro was arrested by police for holding three women captive in his home -- Amanda Berry, Michelle Knight and Gina DeJesus. The women had disappeared separately between 2002 and 2004. They escaped when one of them broke through a door and yelled for help.

It's easy to assume any man who would keep three young women locked in his basement dungeon has some mental problems. Experts told the Huffington Post that Castro was, to say the very least, a control freak, who couldn't stand losing a grip on his own fate.

"This is a guy who lived in a very controlled world –- a universe of his own creation and he was master of that universe," Dr. Scott Bonn, a crime expert and assistant professor of sociology at Drew University, told The Huffington Post.

Dr. Maurice Godwin, a criminal forensic psychologist from Fayetteville, NC, described Castro as the "ultimate sadist."

"Sadists are individuals who enjoy having domination and control over others in order for sexual stimulation," Godwin told HuffPost. "Castro engaged in years of sadistic actions with his victims by inflicting humiliation through the use of physical and sexual abuse."

Still, for what reason did he choose to end his life?

Godwin, who has never treated Castro, believes he suffered from borderline personality disorder (BPD), which drove him to take his own life.

"Castro's suicide was impulsive, which is a trait associated with BPD," he said. "He often acted quickly, without thinking about the consequences. For example, the statistics show that one out of ten people with BPD kill themselves. Not to be confused with having empathy for his victims, individuals with BPD have intense negative emotional experiences; they need find anyway to escape it, and for Ariel Castro, death was certainly his escape."

Bonn believes Castro was disconnected from reality and did not fully grasp the situation he was facing at the time he entered into his plea deal.

"He ultimately found the tables had completely turned and he became the prisoner," Bonn said. "His world was over and I think that was too much for him. I think he had a fragile ego and was a complete control freak. There was no longer a reason for him to live. Suicide became his escape from a life of isolation and powerlessness."

Castro's three victims have yet to comment on his death. While their feelings on the subject remain unclear, Cuyahoga County prosecutor Tim McGinty made no bones about his feelings on Castro's suicide.

"These degenerate molesters are cowards ... This man couldn’t take, for even a month, a small portion of what he had dished out for more than a decade," McGinty said in a press release. "Let this be a message to other child kidnappers: There will be a heavy price to pay when you are caught. You won't enjoy the captive side of the bars."

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  • Ariel Castro

    Convicted kidnapper and rapist Ariel Castro was <a href="http://www.huffingtonpost.com/2013/09/04/ariel-castro-dead-cleveland-kidnapper_n_3863597.html?utm_hp_ref=crime#slide=2450841" target="_blank">found dead</a> on Sept. 3, 2013. On Aug. 1, 2013, Castro was sentenced to life plus 1,000 years in prison for kidnapping and raping Amanda Berry, Michelle Knight and Gina DeJesus, and holding them captive in his Cleveland, Ohio home for more than a decade. He pleaded guilty to 937 counts, including murder and kidnapping, in exchange for the death penalty being taken off the table. According to JoEllen Smith of the Ohio Department of Corrections, Castro was found hanging in his prison cell at the Correctional Reception Center in Orient, Ohio. Although prison medical staff performed lifesaving measures, he was later pronounced dead at the Ohio State University Wexner Medical Center. At the time of his death, Castro was isolated from other inmates for his own protection.

  • Israel Keyes

    Israel Keyes, 34, committed suicide in his Anchorage, Alaska jail cell on Dec. 2, 2012. Prior to his death, authorities say <a href="http://www.huffingtonpost.com/news/israel-keyes" target="_blank">Keyes confessed to being a serial killer</a>, rapist, bank robber and burglar. Authorities suspect Keyes was responsible for nearly a dozen murders.

  • Philip Markoff

    Philip Markoff, a second-year medical student at Boston University School of Medicine, <a href="http://www.huffingtonpost.com/tag/philip-markoff" target="_blank">was charged by police</a> in the 2009 armed robbery and murder of Julissa Brisman in a Boston, Massachusetts. Authorities also suspected Markoff in the robberies of two other women. Markoff met his victims on the online classified website Craigslist, which resulted in his moniker the “Craigslist Killer.” Charged with first-degree murder and other charges, Markoff committed suicide On August 15, 2010, in Boston's Nashua Street Jail. His cause of death was attributed to self-inflicted wounds and suffocation. Prior to taking his life, Markoff reportedly wrote his former fiancee's name in blood on the wall of his cell.

  • Herb Baumeister

    Herb Baumeister was the founder of the Sav-A-Lot thrift store chain in Indianapolis, Indiana, in 1988. Authorities say he was also <a href="http://www.trutv.com/library/crime/serial_killers/predators/baumeister/side_1.html" target="_blank">responsible for the murders</a> of at least 11 men. Investigators found the victims’ bodies in 1996, during a search of Baumeister's 18-acre Marion County estate. Three of the victims have never been identified. Baumeister committed suicide prior to his arrest. He left behind a suicide note, but did not mention any of the murders police say he is responsible for. In addition to the bodies found at Baumeister’s estate, authorities suspect he is also responsible for at least nine other unsolved murders that took place along a corridor between Columbus, Ohio and Indianapolis, Indiana.

  • Leonard Lake

    Arrested for a firearms offense in California on June 6, 1985, <a href="http://www.trutv.com/library/crime/serial_killers/predators/ng/call_1.html" target="_blank">Leonard Lake committed suicide</a> while in police custody by swallowing a cyanide pill. After Lake’s death, authorities connected him, along with co-conspirator Charles NG, to the deaths of at least 11 people, whose bodies were found at Lake's ranch in Calaveras County, California. Authorities suspect the pair could be responsible for at least a dozen additional murders. For his part NG was sentenced to death. He is currently on death row at San Quentin State Prison.

  • Joe Ball

    Often referred to as "The Alligator Man," Joe Ball is <a href="http://www.trutv.com/library/crime/serial_killers/history/joe_ball/index.html" target="_blank">believed responsible for the murders</a> of more than 20 women in Bexar County, Texas, during the 1930s. A handyman who worked with Ball allegedly told authorities Ball fed the bodies of his victims to his pet alligators. On Sept. 24, 1938, Bexar County Sheriff’s deputies confronted Ball about his alleged crimes. Before they could get any answers, he pulled out a handgun and tool his own life.

  • Need help?

    <em class="video_box_subtitle">Need help? In the U.S., call 1-800-273-8255 for the <a href="http://www.suicidepreventionlifeline.org/" target="_hplink">National Suicide Prevention Lifeline</a>.</em>

Need help? In the U.S., call 1-800-273-8255 for the National Suicide Prevention Lifeline.