It takes about three weeks for Americans to stop paying attention after a mass shooting

This is often the unstated goal of gun rights advocates. Allow the passion that immediately follows the attacks to cool, often demanding that politics wait until an appropriate mourning period has passed. Weeks later, most people have moved on to other issues — including members of Congress.

To assess how interest in mass shootings shifted over time, we looked at Google search interest for related terms in the months after high-profile mass shootings. “High-profile” is subjective, but we included incidents tallied by The Washington Post in which more than 10 people were killed or which attracted at least half as much search interest as the shooting at Sandy Hook Elementary in Newtown, Conn., in 2012. (A list of the included incidents is at the bottom of this article.)

Searches for “shooting,” for example, spike immediately after each incident. On average, searches for the term return to pre-shooting level within about 20 days.