Recent mass shooters gunned for "high scores." Are violent video games to blame? Here's everything you need to know:

Why the focus on gaming?
As the country struggles to find an explanation for mass shootings, many elected officials have pointed a finger at violent video games. One of the top video game genres is "first-person shooter," where players get points for stalking and slaughtering other people; terminology from these games is being used by some of the angry young men who have perpetrated the waves of massacres that have stunned Americans. In April, after a 19-year-old indicated on the message board 8chan that he was going to shoot up a synagogue in Poway, California, another 8chan user urged him to "get a high score" — as in, kill a record number of people. Many recent shooters have idolized Anders Breivik, the killer of 77 Norwegians in 2011, who said he "trained" by playing Call of Duty: Modern Warfare 2. In August, a 21-year-old white nationalist who killed 22 people in El Paso, Texas, posted a manifesto about an "invasion" of Hispanics in which he also referenced Call of Duty. In response, President Trump blamed "gruesome and grisly video games."

How violent are today's games?
Grand Theft Auto, one of the top-selling franchises ever, with 285 million games sold, is notorious for letting players "free roam" around a city (based on Los Angeles) and kill random people. The latest installment equips players with Beretta-like pistols, AK-47–like assault rifles, and an arsenal's worth of other guns. In 2003, two teenage brothers said they were acting out Grand Theft Auto 3 when they fatally shot a random motorist in Tennessee. In the gamer world, games like Call of Duty are hailed for their realistic weaponry.

Are shooters usually gamers?
Some are — the Columbine High School killers played the first-person shooter Doom — but just four of the perpetrators of 33 mass murders at U.S. schools between 1980 and 2018 were known to be video gamers. Patrick Markey, a Villanova University psychology professor who studies video games, points out that about 70 percent of U.S. high school students show interest in violent games, but just a tiny minority engage in real violence. Still, the exceptions are disturbing. Adam Lanza, the 20-year-old who killed 26 people at an elementary school in Newtown, Connecticut, was obsessed with violent video games, including one called School Shooting. Nikolas Cruz, the shooter at Marjory Stoneman Douglas High School in Parkland, Florida, played eight to 15 hours of video games a day, his neighbor said: "It was kill, kill, kill, blow up something, and kill some more, all day."

Do games inspire violence?
About 40 percent of Americans think so, yet researchers have spent decades mostly failing to demonstrate such a link. Last year, German researchers divided 77 participants into three groups: One group played Grand Theft Auto V every day for two months, another group played the nonviolent Sims 3, and a control group didn't play any video games. Researchers then measured participants' aggression levels, interpersonal abilities, anxiety, and impulsivity — and found no significant differences. A Dartmouth College analysis of 24 studies that involved 17,000 adolescents came to a somewhat different conclusion: It found that playing violent video games did correlate with increased physical aggression, particularly among children already prone to antisocial behavior. Tim Winter, president of the Parents Television Council, argues that moderate consumption of violent video games may have no effect, but playing them for hours a day can have "a cumulative negative effect" on susceptible minds, and legitimize mass violence.

What do critics propose?
States and the federal government have had limited ability to regulate video games since 2011, when the Supreme Court struck down on First Amendment grounds a California law restricting the sale of ultraviolent games to minors. Justice Antonin Scalia said those games were no more graphic than Grimm's Fairy Tales, calling the law "the latest episode in a long series of failed attempts to censor violent entertainment for minors." As a result of that ruling, politicians who blame violent video games for mass shootings can offer little in the way of policy solutions. In February, Pennsylvania lawmakers proposed a 10 percent sales tax on violent video games; the revenue would be distributed to schools working to install bulletproof glass, metal detectors, and other safety measures.

What is gaming's defense?
Advocates say video games have served as a scapegoat for real-world violence since the 1970s. They note that the highest concentration of video game players is in Japan and South Korea, where many popular titles are shockingly gory, yet those countries experience a minuscule fraction of the gun violence seen in the U.S. "What's new about the current debate," said gaming sociologist Katherine Cross, "is that the scapegoat of video gaming has never been more nakedly exposed for what it is" — a way of avoiding addressing "our nation's permissive and freewheeling gun culture."

Overlapping cultures
Three mass shooters this year announced their attacks on 8chan, which first rose to prominence in 2014 as a place to discuss video games. The message board became a hotbed for racism and misogyny before it was taken offline in the wake of the El Paso and Dayton mass shootings. In March, Brenton Tarrant, 28, posted a manifesto on 8chan before attacking two mosques in Christchurch, New Zealand. He live-streamed his massacre with a helmet cam, positioning the camera so the footage looked eerily similar to a first-person shooter. It quickly went viral, drawing millions of views across Facebook, Reddit, and YouTube. Tarrant's white-supremacist screed made him a hero on 8chan. In April, John Earnest, a 20-year-old from San Diego, defaced a mosque with pro-Tarrant slogans before attacking a synagogue and killing one person. Earnest later posted a statement to 8chan, saying, "I've only been lurking for a year and a half, yet what I've learned here is priceless. Tarrant was a catalyst for me personally." The fact that Earnest had a "score" of only one dead, however, drew derision on 8chan, with one poster saying, "What the f--- shooting style is this. Garbage."