Alyssa Bustamante, a Missouri teenager who strangled and stabbed her 9-year-old neighbor, was sentenced to life in prison with the possibility of parole on Wednesday.

Prosecutors described the 18-year-old as a 'Thrill Killer' who lacked remorse, the Associated Press reported. In 2009, when Bustamante was 15, she strangled her neighbor Elizabeth Olten and stabbed her in the chest before slicing her throat. She told Missouri State Highway Patrol Sgt. David Rice that she always wanted to know what it felt like to kill someone.

In January 2011, Bustamante pleaded guilty to second-degree murder and armed criminal action in the slaying of Olten. Defense attorneys have tried to persuade the court that Bustamante was a disturbed teenager from a broken home, who deserved to be free one day.

The teenager, who was abandoned by her mother and father as a child, has been fighting severe depression for years. In 2007, she tried to commit suicide by overdosing on painkiller. She was later prescribed the anti-depressant Prozac, of which she took an increased dosage before the murder, according to reports. Defense attorneys brought psychiatrist, Edwin Johnston into court, who testified that a higher dosage of the drug could have increased the teenager's mood swings and violent tendencies.

Prosecutors in the murder case have ignored Bustamante's background of depression and focused on the deliberate nature of the murder. Accounts of the murder were recorded in Bustamante's diary and prosecutors used her chilling words in court to try and push for a longer prison sentence.

'I strangled them and slit their throat and stabbed them now they're dead,'' Bustamante wrote in her journal. ''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.

It has been an emotional two-day hearing for the families involved in the case. I think Alyssa should get out of jail the same day Elizabeth gets out of the grave, Olten's grandmother yelled out during one of the testimonies. Bustamante also cried for the first time in the court room when her own grandmother and guardian stormed out of the room.

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