While police would not say how the women were taken captive or whether they were sexually assaulted, Police Chief Michael McGrath told NBC's Today show on Wednesday that investigators found ropes and chains in the house.
He added the women were restrained and "released out in the backyard once in a while."
McGrath said he was "absolutely" sure police did everything they could to find the women over the years. He disputed claims by neighbors that officers had been called to the house before for suspicious circumstances. "We have no record of those calls coming in over the past 10 years," he said.
Amanda Berry, 27, Michelle Knight, 32, and Gina DeJesus, about 23, had apparently been held captive in the house since their teens or early 20s, police said.
A 6-year-old girl believed to be Berry's daughter also was found in the home, police Deputy Chief Ed Tomba said. He wouldn't say who the father was.
About a week ago, Castro took the 6-year-old girl to a nearby park, where they played in the grass, said Israel Lugo, a neighbor who lives down the street. "I asked him whose kid was it, and he told me his girlfriend's daughter," Lugo said.
Women Remain in SeclusionThe women were reunited with joyous family members but remained in seclusion Tuesday. They were rescued after Berry kicked out the bottom portion of a locked screen door and used a neighbor's telephone to call 911. An officer showed up minutes later and Berry ran out and threw her arms around the officer, a neighbor said.
Police identified the other two suspects as the 52-year-old Castro's brothers, Pedro Castro, 54, and Onil Castro, 50. Calls to the jail went unanswered, and there was no response to interview requests sent to police, the jail and city officials.
No charges have been filed against the men, but they could appear in court as early as Wednesday morning.
'The House Was Always Locked'Castro owned the home where the girls were found in a neighborhood dotted with boarded-up houses just south of downtown.
His son, Anthony Castro, said in an interview with London's Daily Mail that he now speaks with his father just a few times a year and seldom visited his house. He said on his last visit, two weeks ago, his father wouldn't let him inside.
"The house was always locked," he said. "There were places we could never go. There were locks on the basement. Locks on the attic. Locks on the garage."
Anthony Castro, who lives in Columbus, also wrote an article for a community newspaper in Cleveland about the disappearance of DeJesus just weeks after she went missing, when he was a college journalism student.
"That I wrote about this nearly 10 years ago – to find out that it is now so close to my family – it's unspeakable," he told the Plain Dealer newspaper.
Ariel Castro Helped Search for Missing WomenMost everyone in the neighborhood knew Castro.
Neighbors say he played bass guitar in salsa and merengue bands and gave neighborhood children rides on his motorcycle.
Tito DeJesus, an uncle of Gina DeJesus, played in bands with Castro over the last 20 years. He recalled visiting Castro's house but never noticing anything out of the ordinary.
Juan Perez, who lives two doors down from the house, said Castro was always happy and respectful. "He gained trust with the kids and with the parents. You can only do that if you're nice," Perez said.
Castro also worked until recently as a school bus driver.
He was friends with the father of Gina DeJesus, one of the missing women, and helped search for her after she disappeared, said Khalid Samad, a friend of the family.
"When we went out to look for Gina, he helped pass out fliers," said Samad, a community activist who was at the hospital with DeJesus and her family on Monday night. "You know, he was friends with the family."
Antony Quiros said he was at the vigil about a year ago and saw Castro comforting DeJesus's mother. One neighbor, Francisco Cruz, said he was with Castro the day investigators dug up a yard looking for the girls.
Castro told Cruz, "They're not going to find anyone there," Cruz recalled.
In 1993, Castro was arrested two days after Christmas on a domestic-violence charge and spent three days in jail before he was released on bond. The case was presented to a grand jury, but no indictment was returned, according to court documents, which don't detail the allegations.
It's unclear who brought the charge against Castro, who was living at the home from which the women escaped Monday. For much more on the Cleveland kidnapping case, including details about the women's harrowing escape, pick up this week's PEOPLE, on newsstands Friday