Ariel Castro has been charged with four counts of kidnapping and three counts of rape.
Castro, 52, looked at the ground while lawyers spoke to the judge. His bail was set at $2 million for each of the four cases, which include the three women and a 6-year-old child who was born in captivity. He did not enter a plea. Prosecutors are considering pursuing the death penalty.
Police say Amanda Berry, 27, Michelle Knight, 32, and Gina DeJesus, 23, were held at the house in a residential area just a few miles from where they disappeared. Investigators said they were held against their will since going missing individually between 2002 and 2004.
While many questions remain about how Castro kept such tight control over the women for so long before their escape Monday, the horrors they suffered are coming to light. Police say Castro, an unemployed, former school bus driver, abducted all the women in the same way, by simply driving up to them and offering them a ride home.
Investigators say the women were chained and roped and kept in different rooms for a decade. Castro told the women there was an alarm system if they'd try to escape. Knight, Castro's first alleged kidnapping victim, was impregnated by Castro five times, but had a miscarriage each time after being beaten by him, reported ABC News affilliate WEWS-TV.
Also in the house was Berry's 6-year-old daughter, Jocelyn. Officials said a paternity test will be conducted to establish whether Castro fathered the child.
A law enforcement source told WEWS-TV that Knight delivered Berry's daughter in a plastic pool "so the mess was easier to clean up." Castro reportedly told her that if the baby died, so would she.
Police said the women remembered being able to go outside twice into the backyard, but they had to wear wigs and sunglasses and keep their heads down. According to ABC News, the 6-year-old was the captive with the most freedom because she occasionally got to leave the house with Castro on walks and to church.
The women were finally freed Monday after Berry's daring escape. According to the WEWS-TV source, Berry saw that a big inside door was left unlocked. She reportedly tried to unlatch a second door but was afraid to break it open because she thought Castro was trying to "test her," the source said.
Berry then saw people outside and screamed for help. Neighbor Charles Ramsey helped kick down the door and called 911.
Knight remained hospitalized Thursday, but Berry and DeJesus returned home on Wednesday.
Authorities say Castro is on suicide watch while in custody. For now, he is the only person being charged in the case. Police initially were questioning his two brothers as well, but investigators say they do not have evidence the brothers played a role in the kidnappings and rapes. The brothers are only facing misdemeanor charges for outstanding warrants not connected to this case.
Law enforcement sources say they've recovered Castro's writings where he describes himself as a "sexual predator." Speaking in Spanish, Castro's own mother called her son "very sick" and apologized to his alleged victims.
DeJesus' mother says she had known Castro for years because she grew up with him. She says after her daughter went missing, he'd ask her how the search was going.
DeJesus told her mother she thought it was OK to go with Castro back in 2004 because he was supposed to take her to meet his daughter, Arlene, who was one of her childhood friends.
In an ironic twist, Ariel Castro's son happened to write an article about the disappearance of DeJesus just weeks after she went missing. In 2004, Anthony Castro was a journalism student and wrote the piece for a Cleveland community newspaper. Anthony Castro said that he's had little contact with his father and that his father deserves to spend the rest of his life in jail. He said he's glad the women are OK.
The Associated Press and ABC News contributed to this report.