"A 70-year-old does it and nobody talks [video games]," he said.

Even if Lanza did play these violent video games, he said, it's "nonsense" to think that a tragedy could have been prevented by removing them from the equation. For example, the 32-year-old Breivik also claimed to be a fan of violent video games such as "Call of Duty," and "World of Warcraft" and said he honed his shooting skills with the games. However, his long manifesto contained even more information on the Byzantine Empire and Muslim expansion, so why not ban history books too, Ferguson wondered.

He concedes many scholars who disagree with him are researching in good faith, but he wonders if spending national attention and money on these issue is worthwhile.

"What's interesting is how eager some segments of society are to grab onto this narrative of violence in video games, just like it was comic books in the 1950s," said Ferguson. "You sometimes see that in a period of moral panic ... It gives us a sense of control over things we can't control."

Other experts argue there may be a link, but its extent is unknown.

A July 2011 study in the Journal of Experimental Social Psychology that looked at 70 young adults found playing violent games may desensitize players to violent imagery in the short-term. Tests showed those who played violent games like "Killzone" and "Grand Theft Auto" behaved more aggressively than those who played nonviolent games. At the time, lead researcher Dr. Bruce Bartholow, associate professor of psychology at the University of Missouri, told CBSNews.com that a single exposure to violent video games would not lead to violence, but this desensitization can occur over time.

"I believe that there is a real reliable link between exposure to violent video games and aggression in the short-term," Bartholow told CBSNews.com Monday. He concedes the effect is probably short-lived, and more research is needed to be done to see how the effects can accumulate over time.

However, he disputes that his study and others like his don't have relevance outside the laboratory. He says there is evidence that suggests they may predict real-world behavior. However, aggression itself is very complex, he says, it would be an oversimplification to say video games could lead to behavior like a violent mass killing.

"Unfortunately I don't think the explanation is very simple," he said. "It might have been one ingredient ... in a whole stew of reasons why someone might do that. In theory, it could be one factor -- but I wouldn't say it's the only factor or the most important factor."