Kierra Johnson, 15, lived a turbulent life that ended in a haze of alcohol and sexual violence on the afternoon of March 7, 2008.

Yesterday, the second young man involved in her death by alcohol poisoning quietly pleaded guilty in a Philadelphia courtroom, as his co-defendant had done in February.

Shareef Clemons, 18, who, if found guilty at trial, could have spent decades behind bars, agreed to plead guilty to rape, conspiracy, involuntary deviate sexual intercourse and simple assault in exchange for a six-to-12-year state prison term, plus five years' probation.

Clemons will be formally sentenced July 28 by Common Pleas Judge Ellen Ceisler, who revoked his bail yesterday and placed him in custody.

Co-defendant Juan Williams, 19, who was prepared to testify against Clemons at trial, will be sentenced by Ceisler May 4.

"We're glad that it ended in a nontrial disposition so that the family didn't have to sit through a trial and listen to all the details of Kierra's last moments of life," Assistant District Attorney Eileen Hurley said after the brief hearing.

Johnson, of East Germantown, gave birth at age 14 and was expelled by the school district to Community Education Partners, a disciplinary school in North Philadelphia, after she was caught having sex on school grounds.

She, Clemons and Williams attended the school, although the boys did not know Johnson.

They met for the first time while waiting at a bus stop on the morning of March 7, 2008, when all three should have been in school.

Clemons, who was 16, and Williams, then 17, didn't even know Johnson's name but recognized her school uniform, they later would tell police.

The trio ended up at Williams' house on Crowson Street near Church Lane, East Germantown, where they drank vodka, wine, peach schnapps and rum.

When Johnson passed out on the living-room sofa, the boys carried her down the basement stairs and placed her on a weightlifting bench, Hurley told the judge.

They put on condoms and took turns having sex with Johnson, who was vomiting and drifting in and out of consciousness.

Clemons also had unprotected anal sex with Johnson, and his DNA was recovered from the victim's body, Hurley said.

The city medical examiner later that day determined that her blood-alcohol level was .433 - rendering her unable to consent to sexual intercourse. That level is also nearly five times above the legal limit to drive a car. When Williams' mother returned home, he ran out the back door, and Clemons told her before fleeing that he and Williams had been in the basement lifting weights. Williams' mother found Johnson unconscious, partly clothed and dangling from the weightlifting bench.