Steven Miles is diagnosed with an autistic syndrome, and claims an alter ego named Ed made him carry out the murder. Surrey Police

British teen Steven Miles, 17, was sentenced to 25 years in prison on October 2 after brutally stabbing and dismembering his girlfriend Elizabeth Rose Thomas, 17 in Oxted, Surrey.Police discovered Thomas' body on January 24, and determined the cause of death to be a stab wound to the back. Miles was arrested on suspicion of murder. Miles plead guilty to the crime on September 9.According to Surrey Police, Miles had dismembered Thomas's body following her death, wrapping up limbs in clingfilm. and had attempted to clean up the crime scene before he was found by a family member. Miles had been reported to be obsessed with the television series "Dexter," which follows the day-to-day life of trained serial killer Dexter Morgan.Miles is also diagnosed with an autistic syndrome and reportedly had an alter ego named Ed, who Miles claims made him carry out the heinous murder.Thomas was described by family members and friends as "'really pretty, really funny and really kind' young lady," according to Surrey Police.This isn't the first time the popular television and literary character has inspired real life crime. Mark Twitchell, 35, was convicted of first degree murder of John Brian "Johnny" Altinger in 2011 after he was inspired by the fictional character.