The horrific allegations were contained in a police report that also said another one of the women, Amanda Berry, was forced to give birth in a plastic kiddie pool.
Cuyahoga County prosecutor Timothy McGinty said his office will decide whether to bring aggravated murder charges punishable by death in connection with the pregnancies that were terminated by force.
"Capital punishment must be reserved for those crimes that are truly the worst examples of human conduct," he said. "The reality is we still have brutal criminals in our midst who have no respect for the rule of law or human life."
Castro, a 52-year-old former school bus driver, is being held on $8 million bail under a suicide watch in jail, where he is charged with rape and kidnapping.
McGinty said Castro will be charged for every act of sexual violence, assault and other crimes committed against the women, suggesting the counts could number in the hundreds, if not thousands.
Among the chilling details in the police report, obtained Thursday by news organizations:
-- Berry, now 27, told officers that she was forced to give birth in a plastic pool in the house so it would be easier to clean up. Berry said she, her baby, now 6, and the two other rescued women had never been to a doctor during their captivity.
-- Michelle Knight, now 32, said her five pregnancies ended after Castro starved her for at least two weeks and "repeatedly punched her in the stomach until she miscarried." She also said Castro forced her to deliver Berry's baby under threat of death if the infant died. Knight said that when the newborn stopped breathing, she revived the child through mouth-to-mouth resuscitation.
-- All three women said Castro chained them up in the basement but eventually let them live upstairs on the second floor. Each woman told a similar story about being abducted after accepting a ride from Castro.
During his brief arraignment Thursday, Castro tried to hide his face, tucking his chin inside his collar. He appeared to close his eyes during the hearing and awkwardly signed documents while handcuffed. He did not speak or enter a plea.
In court, prosecutor Brian Murphy said Castro used the women "in whatever self-gratifying, self-serving way he saw fit."
Kathleen DeMetz, a public defender assigned to represent him at the hearing, didn't comment on his guilt or innocence or object when prosecutors recommended bail be set at $5 million. The judge, instead, ordered Castro held on $8 million.
Castro has been under arrest since Monday, when Berry broke out of his run-down house and called 911 while he was away. Police found the two other women inside. The women had vanished separately between 2002 and 2004 when they 14, 16 and 20.
Berry and former captive Gina DeJesus, 22, went home with relatives on Wednesday. Knight was reported in good condition at a Cleveland hospital.
The police report gave a detailed account of their escape, beginning with Berry's discovery that a door was unlocked, leaving only a bolted outer door between her and freedom.
Berry feared it was a test: She said Castro occasionally left a door unlocked to test them. But she called to neighbors on a porch for help and was able to get out.
Police then entered the house and found the other women, who threw themselves into the officers' arms.
Castro's two brothers, who were arrested with him but later cleared of involvement in the kidnapping case, appeared in court on unrelated charges Thursday and were released.
Ariel Castro's former daughter-in-law, Monica Stephens, told The Associated Press that her former husband said Castro had an extremely violent nature.
"He was always described to me as a violent, just a scary violent person," Stephens said.
"He talked about how his father had beaten him and his mother severely. They were like hostages in their own house. They were locked in," said the woman, who now lives in Florida.
A musician who often practiced at Castro's house said he was there last week and heard noises, "like banging on the wall." Ricky Sanchez said he asked Castro about it, and he blamed it on the dogs. He also said Castro -- a bass guitarist in merengue and salsa bands -- liked to play his music loud.
On his most recent visit, Sanchez said, a little girl came out from the kitchen and stared at him but didn't say anything. He said he also noticed there were four or five locks on the outside door.
"When I was about to leave, I tried to open the door. I couldn't even, because there were so many locks in there," he said.
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