Johnson, a ninth-grade dropout from William Penn High School, told police that he attacked O'Donnell because he wanted to steal her bicycle.
"The way I feel about the whole thing is, I don't like the whole thing," Johnson said in his statement to police June 15, a copy of which the Daily News obtained.
"I shouldn't have did it. I shouldn't have put my hands on her. All over a bike."
About 2:50 a.m., Johnson spotted O'Donnell riding her bike in the area of 4th Street and Girard Avenue, where her Northern Liberties apartment was situated.
"She was about to put the bike up. I grabbed her. I dragged her into the lot," Johnson said, according to the statement. "When I let her go, she fell down on her face. She was unconscious. I took her clothes off [and raped] her."
After the attack, Johnson said he used the victim's keys to get into her building and entered an apartment where a woman was sleeping on a couch. He ran off when the woman awoke and screamed, according to the police statement.
Police found O'Donnell's badly beaten remains in a vacant lot on Orianna Street behind her apartment building. She was nude except for her shoes and a bra that was around her neck.
"That was probably from me trying to take her bra off," Johnson explained in his statement, in which he denied punching O'Donnell.
Assistant District Attorney Richard Sax said that the victim's body was covered with bruises and that Johnson used the bra to strangle her.
"I think he is still in some sort of denial relative to the extent to what he did to her," Sax said after the hearing. "The wounds speak for themselves. They were all over her body."
Regarding Johnson's crying spell, Sax said: "Oft times, you're crying for yourself and the position you put yourself."
The victim's mother, Rachel O'Donnell, was among a group of relatives and friends in attendance who met with Sax afterward.
"I think she is still in shock," Sax said.
Guy R. Sciolla, Johnson's lawyer, declined to comment.