Every time an event like the shootings in Aurora happens the first thing that people ask is: why?
Already the internet is awash with rumour and speculation as to the motives behind the killings which have so far claimed the lives of 12 and seriously injured around 50 others.
The fact that the incident happened at a screening of the new Batman film, 'The Dark Knight Rises' has fuelled a number of 'batty' theories.
One, which depending on your viewpoint is either an eerie coincidence or sinister inspiration, concerns a Batman comic strip called 'The Dark Knight Returns'.
In one scene from the comic a creepy evil-doer named Arnold Crimp who, after listening to Led Zeppelin's Stairway to Heaven backwards and hearing a prayer to the devil, enters a porn theatre and shoots three people dead.
The comic strip was written by Frank Miller 25 years ago and was one of the inspirations behind Christopher Nolan's reworking of the Batman franchise. Miller was also the creative force behind the movies Sin City and 300.