Steven Miles, a British teenager obsessed with the serial killer TV series Dexter was found guilty of murdering his girlfriend, Elizabeth Thomas in the bedroom of his home in Oxted, Surrey, early this year in January. The teen, who had been diagnosed along the autism spectrum, dismembered Thomas in a manner close to Dexter Morgan’s rituals from the show, removing her legs but only a single arm. Then, as Dexter would, Miles placed her body parts in Clingfilm plastic wrap and garbage bags.

Miles told his family he had an alter ego called ‘Ed,’ who often told him to do things, usually involving self-harm. He had been under psychiatric evaluation since 2012. Despite the ‘presence’ of ‘Ed,’ Miles was not deemed schizophrenic. Thomas, meanwhile, would often defend Miles to friends and classmates saying that she’s “fighting for him.”

Miles had long been obsessed with both Dexter but gruesome acts of violence, and had a growing and known interest in killing. According to Miles, ‘Ed’ had given him instructions to kill his girlfriend, telling his sister ‘Ed made me do something bad’ in reference to the murder of Thomas. In his interrogations and court testimony, Miles referred to Thomas only as “the project.”

“This is a case of the utmost gravity, the horrific features of which are rarely heard in any court,” Judge Christoph Critchlow said. “Nothing this court can say or do, no sentence this court can impose can alleviate the pain suffered by Elizabeth Thomas’s family for a death in such a terrible manner. There must be a life sentence.”

Critchlow continued, “You decided, at the age of 16, you had to kill somebody, you chose Elizabeth Thomas, who tragically befriended you and who had stood up for you when people described you as different. It’s chilling to read that you described her on occasion as your project.”

Because of the obvious premeditation, Miles’ lawyers were unable to use any kind of insanity or ‘diminished capacity’ plea. Since the murder happened when Miles was 16—and therefore a minor—his sentencing could not include the death penalty or life in prison.

This is not the first copy-cat Dexter related crime. Over the eight years the show was on the air, there were roughly a dozen unrelated murders around the world meant emulate Dexter’s kills, or where the killers referred to him or the series in their statements.