After taking an increased dose of the antidepressant Prozac, Alyssa Bustamante, who at the time was 15-years-old, strangled and stabbed her 9-year-old neighbor. Defense attorneys will convene in court on Tuesday in an aim to persuade a judge to give Bustamante less than life in prison.

Here are five things to know about the teen killer:

Background

Bustamante,18, came from a broken home. She was abandoned by her mother and her father was in prison for most of her childhood, according to the Associated Press.  Karen Brooke, Bustamante's guardian, told Fox News that's the teenagers mother had suffered from drug and alcohol abuse.

Bustamante has been fighting depression for years. She attempted suicide by overdosing on a large bottle of painkillers, and slashed her skin regularly. She has the word hate carved into her arm.

After recovering from her suicide attempt she was prescribed Prozac and was reported to have increased her dosage before she killed Elizabeth Olten in 2009. Psychiatrist Edwin Johnston said the higher dosage could have increased the teenager's mood swings and violent tendencies.

The Murder

Prosecutors in the murder case emphasized the deliberate nature of Bustamante's actions. They found that Bustamante had dug two graves in advance of the murder. Law enforcement officers discovered a hole in the shape of a grave close to Bustamante's house. Later, Olten's body was found in another grave in the woods. Acknowledging the holes, Bustamante told officials that she liked to dig holes for fun.

Pleaded Guilty

Bustamante admitted killing Olten.  According to Missouri State Highway Patrol Sgt. David Rice, the teenager told him that she always wanted to know what it would feel like to kill someone. In 2009, Bustamante was charged with first-degree murder, but after pleading guilty she avoided a full trail and the possibility of facing life in an adult prison with no chance of being released.

The Diary

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,'

A week before slaying her 9-year-old neighbor, Bustamante had written a diary entry complaining that her phone battery was dead, which illustrated another fight with depression. If I don't talk about it, I bottle it up, and when I explode someone's going to die, she wrote.

Social Media

Bustamante's social media presence shows just how troubled the teen was. On her YouTube page she listed killing people under her hobbies.  On her Facebook profile she posted pictures of her slashed wrists and mouth with lipstick smudges that looked like blood. One photo mimics a gun to her head.

Bustamante's sentencing hearing continues and the teenager is set to appear in court on Tuesday. Olten's mother appeared in court on Monday. She explained how she had reluctantly let her daughter leave that night, asking her to be home before dinner. So much has been lost at the hands of this evil monster, she said. Elizabeth was given a death sentence, and we were given a life sentence.