And yet those who study mass shootings say they are not becoming more common.
"There is no pattern, there is no increase," says criminologist James Allen Fox of Boston's Northeastern University, who has been studying the subject since the 1980s, spurred by a rash of mass shootings in post offices.
The random mass shootings that get the most media attention are the rarest, Fox says. Most people who die of bullet wounds knew the identity of their killer.
Society moves on, he says, because of our ability to distance ourselves from the horror of the day, and because people believe that these tragedies are "1 of the unfortunate prices we pay for our freedoms."