Jefferson City, MO police say that 15-year-old Bustamante confessed to the gruesome murder of 9-year-old Elizabeth Olten, whose throat was slashed and who endured multiple stab wounds; that Bustamante planned the crime in advance; that she hid the body; and that, as the Associated Press summarizes, she did it "without provocation because she wanted to know what it felt like." What's more, Bustamante apparently recorded some of her more disturbing thoughts and actions on social networking sites:

On a YouTube profile viewed by The Associated Press, which has since been taken down, Bustamante listed her hobbies as "killing people" and "cutting." A year ago, Bustamante posted a video to the site in which she appears to intentionally shock herself on an electric fence near her home, then goads her two younger brothers into doing the same.

Alyssa's MySpace and Facebook profiles are locked, but we managed a few glimpses of profiles under cutesy handles Alyssaheartsyou<3 and ramen_noodles_w00t on MySpace and her girly full name, Alyssa Dailene Bustamante, on Facebook:

Like most teens, Bustamante posed for profile pictures that aimed to communicate something about herself. The message is alternately run-of-the-mill and grim. Did the adults in Alyssa's life catch the red flags? Few details about Bustamante's home and school life have emerged, though Fox News reports that Bustamante had been in and out of mental health care facilities:

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    Juvenile officer David Cook testified that Bustamante has received mental health services since September 2007 after she attempted suicide. She had a 10-day stay in the mid-Missouri Mental Health Center after the attempt, and has received mental health services from Pathways Community Behavioral Healthcare in Jefferson City since.

    Cook said Bustamante takes Prozac for depression and also received services for mood swings and self-harm. Cook said Bustamante has a history of cutting herself, but said that there were no indications she was homicidal.

Bustamante has been in police custody since she led authorities to Olten's body on Oct. 23, and was certified this week as an adult so she can be tried as one. 9-year-old victim Elizabeth Olten is remembered as a happy child who loved animals and playing dress up.