A 17-year-old boy with a fixation on a TV serial killer who murdered West Wickham teenager Elizabeth Thomas has been jailed for 25 years.

Steven Miles, 16 at the time, ferociously stabbed his victim before he dismembered her body in the "blood-curdling" killing in his bedroom of his family home in Amy Road, Oxted, Surrey, on January 24 this year.

Elizabeth Thomas was from West Wickham and went to Oxted School. At the time her parents and others in the community paid moving tributes.

Miles stabbed her in the head and back and went on to dismember her legs and an arm, wrapping the limbs in clingfilm and placing them in bin bags, and covered her body in a green plastic garden sheet.

The teenage politics student used saws and tools from his father's tree surgeon business to cut up her body.

Miles, who had been diagnosed as having an autistic syndrome, told his family that he had an alter ego called Ed who had instructed him to kill someone.

When the defendant's sister returned home to the flat about an hour after the murder, Miles told her: "Ed made me do something bad."

During the sentencing hearing at Guildford Crown Court, the court heard that Miles had a fascination with horror movies and the macabre and had wanted to emulate the actions of Dexter, the lead character of an American TV series about a police forensics officer who is also a serial killer.

Judge Christopher Critchlow told Miles: "This is a case of the utmost gravity, the horrific features of which are rarely heard in any court.

"Nothing this court can say or do, no sentence this court can impose can alleviate the pain suffered by Elizabeth Thomas' family for death in such a terrible manner. There must be a life sentence."