The Dark Knight Rises shooting: where does the fault lie?

With the recent shootings in Colorado during a screening of the new Batman movie, we look into whether we can really blame cinema, video games or books for extreme acts of violence.

Plenty of desperately sad stories tumbled out of James Holmes's killing spree in a Colorado cinema last week. But surely the most striking was the revelation that most in the cinema initially thought the masked man who had burst into the screening of Batman and started shooting was part of an elaborate special effect dreamt up by the cinema to celebrate the film's opening night. After all, several Batman fans had dressed up in costume and there was actually a shoot-out occurring on-screen.

Of course, it was shockingly real. This, many have since extrapolated, meant that Holmes was not only familiar with the language of cinematic violence, but seeking to copy it. After all, on his arrest, Holmes, with his dyed orange curls, reportedly told police he was the Batman villain The Joker, who also has coloured hair. And, 12 deaths and hundreds of ruined lives later, the intimation was clear. Could cinema somehow be to blame for such senseless acts?

It's an easy - if simplistic - conclusion to draw, simply because history is peppered with examples. Cho Seung-hui, who in 2007 killed 32 people at Virginia Tech, left a video message which one forensic psychiatrist called a "PR tape of him trying to turn himself into a Quentin Tarantino character". The enjoyably cartoonish violence of Pulp Fiction, it seems, was taken too seriously by Cho.

However, it was the infamous events at Columbine High School in Colorado in 1999 that really opened up a festering, and continuing, debate about the desensitising effects of violence in the entertainment media. Unsurprisingly so, in some respects: the teenagers Eric Harris and Dylan Klebold, who murdered 12 of their peers and one teacher, pulled out their weapons and blasted their classmates to death from behind black trench coats, just as Leonardo Di Caprio had done in the 1995 movie The Basketball Diaries. Indeed, a lawsuit was even filed against the makers of the film by the devastated family of one of the victims, but later dismissed in court.

Harris and Klebold were also huge fans of Natural Born Killers, Oliver Stone's controversial film which, over the years, has been held loosely responsible for eight other copycat murders.

There has been talk of "direct causal links" and more lawsuits, once again thrown out. Natural Born Killers is, if you approach it intelligently enough, actually a satire on a system and society that glamourises violence, in many ways not so far removed from the ground The Hunger Games would cover years later. But not everybody, of course, approached it that intelligently.

Yet there is no real evidence in psychological studies or courts of law that violent movies actively make people commit such atrocities. The effect they do have is to stylise violence in a way that provides a simple road map for incredibly disturbed individuals to carry out their twisted plans.

Take the well-rehearsed arguments about the desensitising effect of violent games on impressionable teenagers. Surely, the reasoning went, it can't be good for kids to be cooped up in their bedrooms, aggressively shooting anything that moves for hours on end. The Columbine murderers, after all, were also big fans of the first-person shooter game Doom. And while the counterargument - that games such as Call of Duty provide some sort of aggression-release mechanism for tortured adolescents - was just as simplistic, there is an age certification system that is meant to be adhered to. The violence, too, is clearly absurd. And with 40 million active players across the Call of Duty franchise alone, it's pretty clear that most people do understand where the boundaries lie.

Of course, in the aftermath of a tragedy such as that one that occurred in Aurora, Colorado, it's natural for people to look for something obvious to blame, rather than try to figure out what made an ostensibly pretty normal student arm himself to the hilt and senselessly murder people. It was interesting, too, that one of the most telling comments of the weekend came from the eminent film critic Roger Ebert. "That James Holmes is insane, few may doubt," he wrote. "Our gun laws are also insane, but many refuse to make the connection ... In theory, the citizenry needs to defend itself. Not a single person at the Aurora theatre shot back, but the theory will still be defended."

Films, video games and books have a right to reflect the bad and good of our society, just as our certification bodies have a right to decide what is and isn't palatable. After that, it's up to the individual to behave decently. After all, John Lennon's murderer Mark David Chapman was obsessed with JD Salinger's The Catcher in the Rye. Is anyone seriously suggesting we ban that, too?