Attendees play the Activision Blizzard Inc. Call Of Duty: Black Ops 4 video game at the company's booth during the E3 Electronic Entertainment Expo in Los Angeles, California, U.S., on Tuesday, June 12, 2018.

After shooting massacres last weekend killed 31 people and wounded dozens, some politicians are once again turning to a familiar scapegoat: video games.

It is a recurring mantra that dates back generations: "violent video games make people more violent." Only, there's no evidence to actually back up that claim, experts say.

"The research is not there to suggest that there is a link between violent video games and these horrific acts of violence," Patrick Markey, director of The Interpersonal Research Laboratory and professor of psychology at Villanova University, said. "When we look at when people play video games, we actually see a dip in violent crimes ... and we don't see an uptick later on."

While some research has suggested the violent video games can cause a slight rise in aggression after being played, Russell Shilling, chief scientific officer at the American Psychological Association, said such cases are a small subset of the population. He was quick to note that aggression doesn't mean violence and that much of these research has been misrepresented in the media.

Markey noted that while over 70% of high school students play violent video games, only 20% of school shooters have reported playing these games.

"School shooters have less interest in violent video games," he said. He added that playing these types of games is normal activity for teens and school shooters tend to not be doing what their peers are doing.