A Missouri teenager who admitted stabbing, strangling and slitting the throat of a young neighbor girl wrote in her journal on the night of the killing that it was an "ahmazing" and "pretty enjoyable" experience _ then headed off to church with a laugh.

The words written by Alyssa Bustamante were read aloud in court Monday as part of a sentencing hearing to determine whether she should get life in prison or something less for the October 2009 murder of her neighbor, 9-year-old Elizabeth Olten, in a small town west of Jefferson City.

Bustamante, 18, sat silently _ occasionally glancing at those testifying about her, often looking down or to the side _ as law enforcement officers, attorneys and forensics experts read aloud her inner most thoughts that she had recorded as a 15-year-old high school sophomore.

The most poignant part of Monday's testimony came when a handwriting expert described how he was able to see through the blue ink that Bustamante had used in an attempt to cover up her original journal entry on the night of Elizabeth's murder. He then read the entry aloud in court:

"I just f------ killed 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."

Bustamante pleaded guilty to second-degree murder and armed criminal action last month and faces a sentence of 10 years to life in prison with the chance for parole. Autopsy results revealed in court Monday show Elizabeth was strangled so hard it could have caused brain death, had throat slits potentially indicative of torture and was stabbed eight times in the chest.

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.

After the suicide attempt, Bustamante was prescribed the anti-depressant drug Prozac. Just two weeks before killing Elizabeth, Bustamante started taking a higher dosage, which a defense psychiatrist testified could have increased her mood swings and tendency toward violence.

"I think it was a major contributing factor" in Bustamante's slaying of Elizabeth, testified psychiatrist Edwin Johnston, of Houston.

The defense will continue making its case Tuesday.

Earlier Monday, Elizabeth's relatives pleaded with Cole County Circuit Judge Pat Joyce to impose the maximum sentence.

Elizabeth's mother, Patty Preiss, described her daughter as "happy, little girl," when she left her home about 5 p.m. after begging to go play with Bustamante's younger sister. Preiss said she told Elizabeth to be back for dinner at 6 p.m. but never saw her again.

"So much has been lost at the hands of this evil monster," Preiss tearfully said, with Bustamante sitting several feet away. "Elizabeth was given a death sentence and we were given a life sentence."

With Bustamante looking at her, Preiss said: "I hate her, I hate everything about her." The judge cut off her testimony when she described Bustamante as "not even human."

At a hearing in 2009, Missouri State Highway Patrol Sgt. David Rice testified that Bustamante had told him she "wanted to know what it felt like" to kill someone. He did not repeat that Monday, because part of Bustamante's statement to police was suppressed by the judge.

Instead, prosecutors used Bustamante's own words from her journal, which was seized by FBI agents from Bustamante's bedroom the day after Elizabeth went missing, as hundreds of volunteers scoured the rural area around their St. Martins home.

The journal entries began about two months before Elizabeth's murder, and included several references to suicidal thoughts. At one point, Bustamante wrote that she intended to burn down a house and kill all the occupants, but she never followed through with that. On Oct. 14, one week before Elizabeth's slaying, Bustamante wrote that she was unable to use her cell phone because the charger had died, which meant she couldn't talk to anyone about the depression and rage she was feeling.

"If I don't talk about it, I bottle it up, and when I explode someone's going to die," she wrote in a journal entry that was read to the court by her defense attorney, Charlie Moreland.

The night of the slaying, Bustamante later went to a youth dance at her church. Her grandmother was asked in court if she noticed anything different as they left the home. She said Bustamante seemed happier than normal.