But those who know the 52-year-old Castro are speaking up, saying he was often angry, paranoid and prone to violent outbursts against the mother of his children. He frequently beat her, played bizarre psychological games and locked her indoors, they said.
The stories, repeated in separate interviews with The Associated Press by members of Castro's extended family, have surprised people who knew him as a musician who played bass in several bands around Cleveland the last two decades.
Miguel Quinones, manager of a group Castro played with twice as a backup bass player about five years ago, said he had nothing bad to say about Castro based on his own experiences.
But in the interviews, some of Castro's ex-relatives said he frequently flashed his compulsions for secrecy and terrifying rage that often led him to beat his common-law wife, Grimilda Figueroa.
Figueroa left Castro years ago and died in 2012 after a long illness. Their early years together were happy, but something inside Castro snapped after the birth of their first child, they said.
Castro pushed her down the stairs, fractured her ribs, broke her nose several times, cracked a tooth and dislocated both shoulders, they said. In one incident, he shoved Figueroa into a cardboard box and closed the flaps over her head, they said. He kept her and children imprisoned, cut off from friends and family, and Figueroa couldn't even unlock her own front door, they said.
Figueroa filed domestic-violence complaints, accusing Castro of threatening many times to kill her and her daughters. She charged that he frequently abducted the children and kept them from her, even though she had full custody, with no visitation rights for Castro.
"When I go over there to visit her, and I ask her, 'Nilda, I'm here, open the door,' she's like, 'I can't. Ariel has the key,'" Figueroa's sister, Elida Caraballo, recalled.
Two of the women freed from Castro's home, including the one who gave birth to the girl, returned to relatives' houses earlier this week. The third woman, Michelle Knight, was released from a hospital Friday with a request that her privacy be respected.
"Michelle Knight is in good spirits and would like the community to know that she is extremely grateful for the outpouring of flowers and gifts," the statement said.
On Friday, Knight's grandmother, Deborah King, visited the home of one of the captives, Gina DeJesus, to meet the DeJesus family.
She said she loved and missed Knight, "And if I get to, she's going to get the biggest hug and kiss from me that she ever did have."
A police report alleged that Castro impregnated one of his captives at least five times and made her miscarry by starving her and punching her in the stomach. The report also said another one of the women, Amanda Berry, was forced to give birth in a plastic kiddie pool.
Tests by the state attorney general's office on a sample of Castro's DNA confirmed he fathered Berry's 6-year-old daughter, who was rescued from his house, the office said Friday. After her release, the girl returned home with the 27-year-old Berry. Officials also were entering the DNA profile into a national database to see if it links him to other crimes.
The three women said Castro chained them up in the basement but eventually let them live on the home's second floor. Each woman told a similar story about being abducted after accepting a ride from him.
The FBI has not recovered human remains in its search of the house, spokeswoman Vicki Anderson said Friday. Agents removed more than 200 pieces of evidence, she added, declining to say what was found.
Berry and former captive Gina DeJesus, 22, went home with relatives Wednesday.
The AP does not usually name people alleging sexual assault without their consent, but the names of the three women were widely circulated by their families, the media and law enforcement for years.