Alyssa Bustamante
Alyssa Bustamante pleaded guilty to one count of second-degree murder after strangling, stabbing and slitting the throat of her 9-year-old neighbor Elizabeth Olten. The Missouri 18-year-old, who was 15 at the time of the murder, was sentenced to life in prison with possibility of parole on Wednesday.Dr. Edwin Johnstone, a consulting psychiatrist who testified on Bustamante's behalf in court, said that changes in her Prozac prescription could have played a part in mood swings that may have contributed to Bustamante's murderous tendencies. People who were prescribed Prozac "were showing an abundance of suicides and violent events, including homicides,” Johnstone told the court.

A Missouri teenager who admitted killing a nine-year-old girl wrote casual diary entries reading: "I just killed someone... it was ahmazing!" just hours after the crime.

Alyssa Bustamante, then 15, wrote the entry soon after killing Elizabeth Orten. The chilling entry was read out in court where Bustamente is on trial for murder.

"I just f***ing killed someone. I strangled them and slit their throat and stabbed them now they're dead. I don't know how to feel atm [at the moment].

"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"

Bustamante faces between 10 years in jail and life imprisonment. Defence lawyers have asked for leniency based on the her alleged depression and suicidal tendencies.

Juvenile justice officials said that Bustamante, now 18, had attempted suicide at the age of 13 and had received mental health treatment for depression and self-harm.

Elizabeth's family have called for the girl to be given the maximum penalty.

Prosecutors said that Bustamante plotted the death of her neighbour and before the murder dug two holes to bury her.

Sgt David Rice told the court she had confessed to the killing and showed the police to her grave.