CLEVELAND >> Ariel Castro intentionally left doors unlocked at his house in the months before three women escaped after nearly a decade of captivity because he knew the end was near, his former defense attorney said.

Castro felt that the young girl he fathered with one of his captives was getting older and needed to be in school with a life outside the house, attorney Craig Weintraub told WKYC in Cleveland.

"He didn’t have the courage to go to the police department and surrender, and the only way this was going to happen is if he was negligent and allowed them to leave the house and be able to find a way out while he was gone a few hours," Weintraub said.

Tuesday is the anniversary of the escape from the house by Michelle Knight, Amanda Berry and Gina DeJesus, whose breakout and subsequent recounting of the horrors they suffered during their time in captivity drew substantial attention. Castro pleaded guilty to a long list of charges last August and soon after committed suicide in prison.

Weintraub, one of two attorneys who represented Castro, said that Castro decided not to kill the three women because he had become close to the child he had with Berry.

DeJesus, Berry and Knight disappeared separately between 2002 and 2004 in Cleveland. They were rescued from Castro’s run-down house May 6, 2013, after Berry broke through a screen door. Police found DeJesus and Knight upstairs where there were bedrooms outfitted with chains and locks.

According to police documents released this week, Berry told authorities after she escaped: "He didn’t lock the door, he always locks the doors. I thought it was a trick but I had to take that chance."

Another document recounted a conversation Castro had with a police officer shortly after he was arrested. The officer, who had known Castro since childhood, asked him how he had kept the women for so long without anyone finding out.

"It was hard, but it was my secret, and I’m glad that it is over," Castro told the officer. "Now I can die in prison, but I’m a victim, too."

Castro told investigators that he was sexually abused by a man when he was a young boy, the documents said.

Berry and DeJesus were honored by the National Center for Missing and Exploited Children on Tuesday night in Washington.

They both said in statements Monday that they were thankful for support from their families and the community and that they growing in many ways.

Michelle Knight said in an interview on NBC’s "Today" show Monday that Castro deserves forgiveness because she’d want to be forgiven if she did wrong, and "that’s the way of life."