Cleveland kidnapper Ariel Castro became the seventh Ohio prisoner to commit suicide this year, the Ohio Department of Corrections told International Business Times.

Castro, 53, agreed to a plea deal that gave him life in prison and spared him the possibility of the death penalty after admitting to kidnapping and repeatedly raping Amanda Berry, Michelle Knight and Gina DeJesus over a 10-year period. He killed himself in his cell Tuesday night after prison officials found him hanging from bed sheets.

Castro is the first prisoner to commit suicide in Ohio since death row inmate Billy Slagle hanged himself in his cell in August, days before he was set to be executed. At the time Slagle killed himself, the rate of suicide in Ohio’s jails and prisons was below the national average since January 2008, the Lancaster Eagle-Gazette reported.

While Castro is the most recent high-profile prisoner to commit suicide, he isn’t alone. Here are some other notable prisoners who killed themselves in their cells:

Israel Keyes

Suspected serial killer Israel Keyes committed suicide in December 2012 while being held in an Alaskan jail for the murder of 18-year-old Samantha Koenig. The enigmatic Keyes killed himself by strangling himself and cutting his wrists.

“He wanted to avoid numerous trials in different jurisdictions,” said FBI Special Agent Jolene Goeden. “Ultimately, he wanted the death penalty and he wanted it quickly. He didn’t want to sit in jail for a long period of time.”

The FBI had a number of sit-downs with Keyes in trying to solve a number of murders across the country. Due to his death, many of the cases remain unsolved, leading the bureau to appeal to the public for information.

“He gave us a number of clues,” said Goeden, an agent in the FBI’s Anchorage Division. “He talked openly about some of the homicides, but much of what he said only hinted at the things he had done. So we are trying to get information out there about what he did tell us. We are letting the public know the types of cars he rented, towns he visited, campgrounds he frequented. Anything that might spur someone’s memory could help us,” Goeden said.

Philip Markoff

Known as the “Craigslist Killer,” Markoff was suspected of robbing and killing Craiglist masseuse and model Julissa Brinkman in Boston in April 2009. Markoff chillingly committed suicide in August 2009 in Boston’s Nashua Street Jail by cutting and suffocating himself. He used his blood to write “Megan,” the name of his fiancée, Megan McCallister, on the walls of his cell. Markoff chose to commit suicide one year and one day after he and McCallister were to get married.

Markoff made previous suicide attempts and was scheduled to face murder and gun charges at a trial scheduled to begin in March 2011.

Markoff was also suspected of robbing escort Trisha Leffler and exotic dancer Corinne Stout, whom he allegedly met up with after arranging encounters on Craigslist.

Ryan Brunn

Ryan Brunn hanged himself in his Georgia prison cell in January 2012, two days after being sentenced to life in prison for the molestation and murder of 7-year-old Jorelys Rivera.

While pleading guilty to the crimes, Brunn said he killed the girl because he was worried about Jorelys reporting the molestation to her parents.

"I didn't want her to go home and tell her mom or dad on me," he said. "So I cut her."

Brunn’s suicide came as a relief to Jorelys’ family.

“This is the kind of justice that I was expecting for him for all the damage that he made to my little daughter,” the girl’s mother, Jocelyn Rivera, told the Atlanta Journal-Constitution at the time. “Now, I can say that I feel satisfied.”