A teenager who said strangling, cutting and stabbing a 9-year-old girl was “ahmazing” was sentenced to life in prison with possibility of parole.

Alyssa Bustamante, 18, pleaded guilty in January to second-degree murder and armed criminal action in the October 2009 slaying of Elizabeth Olten in St. Martins, a small rural town west of Jefferson City. She told investigators she stabbed the girl repeated in the chest and slashed her throat because she wanted to know how it felt to kill someone.

I strangled them and slit their throat and stabbed them now they're dead. I don't know how to feel atm. It was ahmazing. As soon as you get over the 'ohmygawd I can't do this' feeling, it's pretty enjoyable. I'm kinda nervous and shaky though right now. Kay, I gotta go to church now...lol.

- Alyssa Bustamante in her diary entry after the killing

Bustamante, who was 15 at the time of the killing, had been charged with first-degree murder and by pleading guilty to the lesser charges she avoided a trial and the possibility of spending her life in an adult prison with no chance of release.

Bustamante led police to the shallow grave where she had concealed Elizabeth's body under a blanket of leaves in the woods behind their neighborhood.

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The teenager's defense attorneys had argued for a sentence less than life in prison, saying Bustamante's use of the antidepressant Prozac had made her more prone to violence. They said she had suffered from depression for years and once attempted suicide by overdosing on painkillers.

But prosecutors sought a longer sentence. They noted that Bustamante had dug two graves several days in advance, and that on the evening of the killing had sent her younger sister to lure Elizabeth outside with an invitation to play. Missouri State Highway Patrol Sgt. David Rice testified that the teenager told him "she wanted to know what it felt like" to kill someone. Prosecutors also cited journal entries in which Bustamante described the exhilaration of killing Elizabeth.

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"I strangled them and slit their throat and stabbed them now they're dead," Bustamante wrote in her diary, which was read in court by a handwriting expert. "I don't know how to feel atm. It was ahmazing. As soon as you get over the 'ohmygawd I can't do this' feeling, it's pretty enjoyable. I'm kinda nervous and shaky though right now. Kay, I gotta go to church now...lol."

Bustamante then headed off to a youth dance at her church while a massive search began for the missing girl.

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Testifying in her defense, Bustamante's imprisoned father described a family history of drug abuse, depression and suicide attempts. Her legal guardian and grandmother, Karen Brooke, testified how Bustamante's mother abandoned her children shortly before Bustamante attempted suicide in on Labor Day 2007 by swallowing a large bottle of Tylenol and making hundreds of cuts on her arms — even carving the word "hate" in one of them.

Based on reporting by The Associated Press.

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