Bind. Torture. Kill. 10 victims. A series of taunting letters to police, newspapers, and an intended victim who wasn't home. One floppy disc, leading to his arrest. Explaining what drove the killer to murder these 10 people, and then taunt police, is the objective of this 2008 film, which dramatises the events between 1974 and 1991, and then the 2005 arrest of the BTK killer, Dennis Rader.