Do some kinds of video games cause violence? Scientific studies do not suggest a link. But the idea that there is a link between violent video games and violent acts reappeared following the mass shooting in El Paso, Texas, last weekend. An online statement thought to be written by the El Paso gunman mentioned the combat game “Call of Duty.” On Monday, President Donald Trump said that “gruesome and grisly video games” contribute to a “glorification of violence.” American politicians have long made similar statements. “Politicians on both sides go after video games…it is this weird unifying force,” said Patrick Markey, a psychology professor at Villanova University who studies video games. Benjamin Burroughs is a professor of media at the University of Las Vegas. “There is no linkage to gun violence,” he said about video games.