Alyssa Bustamante is the ghoul who murdered a nine-year-old girl just to see what it felt like.
Bustamante cut the throat of little Elizabeth Olten, then buried the girl's body in a grave she had already prepared.
Now, the victim's heartbroken mother spoke to INSIDE EDITION and ripped into the teenage killer.
Patty Preiss wiped away tears as she spoke to INSIDE EDITION's Paul Boyd about the murder that shocked the nation.
"She's not human. There's no way she could even be human to do that to a child," Preiss said to Boyd.
Her daughter Elizabeth Olten went outside to play near Jefferson City, Missouri, and was lured into the woods by neighbor, Bustamante. Bustamante strangled the little girl, stabbed her and cut her throat. She described it in her diary as "Ahmazing."
Boyd asked Preiss, "She had a grave ready to bury her, didn't she?"
Preiss responded, "Yes,"
Boyd then asked, "Why?"
"For her own enjoyment. She wanted to know what it was like to kill somebody," said Preiss.
In her diary Bustamante, who was just 15 at the time, wrote, "I just (blank)ing killed someone. It's pretty enjoyable."
Incredibly, she then wrote, "Kay, I gotta go to church now... lol."
Elizabeth's mom showed Boyd a scrapbook filled with pictures of Elizabeth, who loved dogs, adored dressing up, and always had a big smile for everyone.
"I can imagine how scared she was," said Preiss.
Bustamante, now 18, was sentenced to life in prison last week, but is still eligible for parole in 35 years, when she'd be in her early fifties.
Elizabeth's mom is furious about a deal that allowed her daughter's killer to plead guilty to second-degree murder.
She says the D.A. told her he made the deal because he was worried a jury might let Bustamante walk free - just like Casey Anthony.
"His excuse was 'Look at the Casey Anthony trial. Any jury can do anything.' I told him, 'Look at the Casey Anthony trial, look at how mad all the people are for Casey getting off.' "
Bustamante apologized for the murder in court, saying: "If I could give my life to get her back I would. I'm sorry."
But Elizabeth's devastated mother doesn't buy it. "She took Elizabeth's life with no hesitation at all," said Priess.