PHILADELPHIA (AP) _ A girl who admitted stabbing a stranger to death when she was 11 years old will stand trial as an adult, after a plea agreement proposed by a judge fell apart.

Miriam White, now 13, could now be sent to an adult prison if she is convicted. She is among the youngest girls in the nation to be charged with murder.

The proposed plea agreement had called for White to be released at age 21, followed by adult probation and treatment until age 46.

``The hybrid solution _ which would give Miriam treatment in the juvenile system as a youth and supervision in the adult system after adulthood _ will not happen,'' Philadelphia Common Pleas Court Judge Legrome D. Davis Jr. said Thursday.

Defense lawyer Thurgood Matthews said he rejected the deal because he thought his client would remain behind bars, not in the $25,000-a-month treatment center, if he accepted.

Without an agreement, Davis had only two choices _ adult court or juvenile court. In the juvenile system, White would automatically go free at age 21, without any legal supervision. The judge would not agree to that.

White is accused in the death of Rosemarie White, a 55-year-old hairdresser. The victim was stabbed in the heart with a kitchen knife in August 1999 as she stood outside with her dog.

In the hours afterward, the girl told police she grabbed a knife and ran outside after an argument at home about the family cat getting out. She said she wanted to be sent back to a youth facility.

Born to drug-addicted parents, the girl was put in foster care at age 3 because of abuse and neglect. At the time of the stabbing, she was living with a woman who hoped to adopt her and has stood by her in court.