Alyssa Bustamante, 18, received a sentence of life in prison on Wednesday for the murder of her 9-year-old neighbor two years ago.
Bustamante expressed her regret in Wednesday's hearing, saying she'd give her own life to bring back her victim.
Bustamante's journal was a key piece of evidence in her trial.
In that journal, she wrote that the experience of murdering the girl was "ahmazing."
Bustamante is eligible for parole.