All four video games do exhibit “blood and gore” and “intense violence,” according to the Entertainment Software Rating Board, but many researchers are skeptical that there is a direct link between violent media and aggression in viewers. Violent-crime offenses decreased about 20 percent from 1998 to 2011, according to the FBI, while video game sales more than tripled, to $16.6 billion last year, according to the Entertainment Software Association…

LaPierre on Friday also assigned blame for mass shootings to music videos that “portray murder as a way of life” and to “blood-soaked films” such as “Natural Born Killers” and “American Psycho.”

Some research books, journal articles and dissertations suggest there is no direct correlation between an Oliver Stone movie about renegade criminals and a mass shooting like the one in Newtown. A 2009 article in the Journal of Pediatrics titled “The Public Health Risks of Media Violence: A Meta-Analytic Review” did not find “either a causal or correlational link between violent media and subsequent aggression in viewers.” The results of two peer-reviewed studies published in a 2008 issue of the journal Criminal Justice and Behavior suggest that “playing violent video games does not constitute a significant risk for future violent criminal acts.”