If it seems like mass shootings are becoming more common, researchers say they are, reports the Los Angeles Times. Between a 2011 shooting at a restaurant in Carson City, Nv., that left four people dead and the 2013 attack on the Washington Navy Yard where 12 people were killed, a mass shooting occurred somewhere in the U.S. once every 64 days, on average. In the preceding 29 years, such shootings occurred on average every 200 days, say researchers from Harvard University’s School of Public Health and Northeastern University. The study defined a mass shooting as an outbreak of firearms violence in which four or more victims were killed and the shooter was unknown to most of his victims.
Not only are such shootings more common, they have also become more deadly. In the 10-year period that ended with the Washington Navy Yard attack, 285 people died in such events. In the 13 years before that, 151 people perished in mass shootings. Between Jan. 1, 2015 and July 20, 2015 there have been 203 mass shooting events in which victims were both killed and wounded by gunfire, according to statistics from Mass Shootings Tracker, a Wiki-style site. That doesn’t include the two moviegoers who were killed and nine wounded at the Grand Theatre multiplex in Lafayette La., last Thursday night. Although the fatalities in mass shootings are dramatic, they are dwarfed by the number of people killed by firearms in attacks that affect one or two victims at a time and largely escape public notice. The Centers for Disease Control and Prevention estimated that 11,208 people died in homicides involving firearms in the United States in 2013.