Shooters killed 14 people at a social services center in San Bernardino, California on Wednesday (Dec. 2). In the United States, it’s not only the largest mass murder of 2015, but of the past three years. Not since a gunman killed 20 children, six adults, his mother and himself in Newtown, Connecticut at the end of 2012 has a mass shooting claimed so many lives.
The first shooting in the above chart shows the 28 killed in Newtown on December 14, 2012. The last shows the mass shooting in San Bernardino. The largest mass shooting between them, on September 16, 2013, was the incident at the Washington Navy Yard, where a gunman killed 12 people.
There have been 16 shootings so far in 2015 that have resulted in the deaths of 5 people or more, including the incident on Wednesday, according to data from Mass Shooting Tracker. Many of the mass shootings this year resulted no deaths, according to that dataset, because it defines mass shootings as any incident where four or more people were shot–whether or not anyone was killed. The dataset also counts the death of the shooter in cases where he committed suicide after the fact.
Mass shootings in 2015 surged over the summer months, as violent crimes often do, then began to decline in September and October. But the number of incidents surged to 33 in November, and as of the second day of December, the incident in San Bernardino was not the only mass shooting of the month. In fact, it wasn’t even the only mass shooting of the day. On the other side of the country, in Georgia, a gunman shot four people on Wednesday, killing one.