We have reached a point in America at which mass shootings happen so often that the country sometimes only has a few days — sometimes only a few hours — to catch its breath in between. When the shooter is white and male, as mass shooters so often are, the narrative of the “lone wolf” quickly becomes dominant. Anti-gun control ideologues, from the National Rifle Association to Republican lawmakers, assure us that the shooter was a monstrous singularity, just one bad guy who happened to have a gun.

But it takes a village to unleash a mass shooting. It is never solely the result of one person’s evil intentions. Many mass shootings could never have taken place without the fuel of racist and misogynist propaganda, or the help of unscrupulous purveyors of the weapons of war, or the failure of public venues to implement effective security measures.

The last factor was highlighted in the Oct. 3 announcement that MGM International would be paying roughly $800 million to settle lawsuits filed by victims of the 2017 Las Vegas shooting. MGM International owns the Mandalay Bay Hotel, where bullets were fired from the 32nd floor onto thousands attending a country music festival in October 2017. When it was over, 58 people were dead and hundreds were injured, in the deadliest mass shooting in United States history. Victims alleged that lax security at the hotel, where the shooter was able to bring more than 20 suitcases full of firearms and ammunition to his room over several days, made MGM partly responsible for the killings.

The MGM settlement illustrates the principle of collective responsibility, under which third parties can be considered responsible for harmful acts they did not cause but did not do enough to prevent. Collective responsibility, or secondary liability, is a common theme in the law. Bartenders who serve alcohol to obviously inebriated patrons can be sued if those patrons cause car accidents; grocery stores can be held accountable for failing to clean up spills that lead to injuries; employers can be liable for failing to respond to reports of sexual harassment. Such entities are often said to have breached a “duty of care,” and imposing liability is intended to give them incentive to be more careful in the future.