The Death Toll of a Mass Shooting Doesn’t End at the Scene

When a mass shooting tears through an American community, we count the dead. That number—26 at Sandy Hook Elementary, 49 at Pulse nightclub, 58 in Las Vegas—becomes the headline, the official measure of the scope of the horror. But anyone who has watched the alerts pile up on their phone, felt their stomach drop, and struggled to focus for the rest of the day knows the damage doesn’t stop at the victims. It ripples outward across the country, affecting in one way or another millions of Americans who were nowhere near the scene.Intuitively, we can all sense the broader harm, but it is remarkably hard to measure. Nearly two-thirds of Americans say mass shootings are a significant source of stress in their lives. Researchers have found that after these events, antidepressant use rises among teenagers living near a school shooting. Gun purchases made in response to events have been shown, grimly, to lead to still more accidental gun deaths. In a recent study published in JAMA Psychiatry, we set out to measure another channel through which a mass shooting’s harm could quietly spread: deaths on the road.At first glance, it might seem like mass shootings and car crashes have little to do ...