Has the rate of random mass shootings in the United States increased? Over the past 30 years, the answer is definitely yes. It is also true that the total U.S. homicide rate has fallen by over half since 1980, and the gun homicide rate has fallen along with it. Today, Americans are safer from violent crime, including gun homicide, than they have been at any time since the mid-1960s.

Mass shootings, defined as four or more fatalities, fluctuate from year to year, but over the past 30 years there has been no long-term increase...