Investigators said the women apparently were bound with ropes and chains, and a city councilman briefed on the case said they were subjected to prolonged sexual and psychological abuse and suffered miscarriages.
Ariel Castro, a 52-year-old former school bus driver, was charged with four counts of kidnapping - covering the captives and the daughter born to one of them - and three counts of rape, against all three women.
The women, now in their 20s and 30s, vanished separately between 2002 and 2004. At the time, they were 14, 16 and 20 years old.
Prosecutors brought no charges against Castro's two brothers, who were arrested along with him on Monday, saying there was no evidence they had any part in the crime.
Castro owns the run-down home where the women were rescued on Monday after one of them, Amanda Berry, broke through a screen door to freedom while he was away. The discovery electrified Cleveland, where many people had come to believe the missing young women were dead.
Police Deputy Chief Ed Tomba said it was the only opportunity they ever had to escape.
"Something must have clicked, and she saw an opportunity and she took that opportunity," he said.
Tomba said the women could remember being outside only twice during their time in captivity.
"We were told they left the house and went into the garage in disguise," he said.
The women were not kept in the same room but knew about one another, he said.
He also said a paternity test on Castro was being done to establish who fathered Berry's 6-year-old daughter.
At a news conference, authorities would not discuss the circumstances of the women's kidnappings or give further details about their ordeals. But City Councilman Brian Cummins said: "We know that the victims have confirmed miscarriages, but with who, how many and what conditions we don't know."
"It sounds pretty gruesome," he added.
Castro was in custody Wednesday and couldn't be reached for comment. A brother-in-law has said the family was shocked after hearing about the women at the home.
Neighbors said that over the years, Castro took part in the search for one of the women, Gina DeJesus, helped pass out fliers, performed music at a fundraiser for her and attended a candlelight vigil, at which he comforted her mother.
None of the women said anything that indicated Castro's brothers, Pedro Castro, 54, and Onil Castro, 50, were involved, Tomba said.
"Ariel kept everyone at a distance," he said.
A court hearing for Ariel Castro was set for Thursday morning.
The deputy chief also said there was no evidence to indicate any of the women had been outside without clothes, despite claims from a neighbor who said a naked woman was seen crawling around the backyard.
Cleveland police have disputed claims by neighbors that officers had been called to the house before for suspicious circumstances. They said nothing in their records supports that.
Earlier Wednesday, Berry, 27, and DeJesus, who is in her early 20s, were welcomed home by jubilant crowds of loved ones and neighbors with balloons and banners. Family members protectively took them inside, past hundreds of reporters and onlookers.
Neither woman spoke.
"Give us time and privacy to heal," said Sandra Ruiz, DeJesus' aunt. Ruiz urged the public not to retaliate against the Castros or their families.
DeJesus' father pumped his fist after arriving home with his daughter and urged people across the country to watch over the children in their neighborhoods, including other people's kids.
"Too many kids these days come up missing, and we always ask this question: How come I didn't see what happened to that kid? Why? Because we chose not to," he said
The third captive, Michelle Knight, 32, was reported in good condition at Metro Health Medical Center, which a day earlier had reported that all three victims had been released. There was no immediate explanation from the hospital.
The Associated Press does not usually identify people who may be victims of sexual assault, but the names of the women were widely circulated by their families, friends and law enforcement authorities for years during their disappearances and after they were found.
Castro also was questioned about 14-year-old Ashley Summers, who disappeared near his house in 2007. But Tomba said there was no new information linking that case to Castro.
While prosecutors announced charges against Castro, federal agents searched a vacant house near where the women had been held. Officials would not say why they were there.
A 2005 domestic-violence filing in Cuyahoga County Domestic Relations Court accused Castro of twice breaking the nose of his children's mother, knocking out a tooth, dislocating each shoulder and threatening to kill her and her daughters three or four times in a year.
The filing for a protective order by Grimilda Figueroa also said that Castro frequently abducted her daughters and kept them from her. Figueroa died a year ago.
Associated Press writers Andrew Welsh-Huggins, Jesse Washington and Mike Householder and freelance reporter John Coyne in Cleveland; Mitch Stacy in Columbus; Dan Sewell in Cincinnati; John Seewer in Toledo; and news researchers Rhonda Shafner and Jennifer Farrar in New York contributed to this report.