Mark Twitchell is a Canadian filmmaker from Edmonton who was convicted of first-degree murder in the 2008 killing of Johnny Altinger. Obsessed with the TV show Dexter, Twitchell lured his victim through an online dating ad and murdered him in a garage outfitted like a kill room, mirroring scenes from the show. Investigators later found a detailed document on his laptop titled "SK Confessions," which outlined the crime in disturbing detail. Twitchell was sentenced to life in prison with no chance of parole for 25 years.