41 Years of Mass Shootings in the U.S. in One Chart

There have been at least four mass shootings so far in 2021, all of which have come in the last month and have left a total of 30 people dead and at least seven injured. The incidents serve as a reminder that, after a brief lull in 2020 when only two incidents met the formal definition of a mass shooting, leaving nine victims dead, the horrific and regular spates of public gun violence that have plagued the country for at least four decades are not over.

A database of mass shootings compiled by Mother Jones going back to 1982 counts 123 such incidents in which at least three people were killed, not including the gunman. In that time, 952 people have been killed and 1,315 wounded. The following chart visualizes each mass shooting in terms of deaths and injuries. TIME has examined each incident and slightly adjusted some values as the death toll and number of injured has been clarified over time.

America’s mass shooting epidemic defies not only one’s sense of humanity, but also the basic practice of counting. There are several common means of tallying mass shootings with widely divergent results, based on, for example, whether one limits to incidents of indiscriminate killings versus targeted homicides. As Mother Jones‘ Mark Follman notes, the actual number of fatalities is probably higher. A 2013 federal mandate authorized by President Obama lowered the definition of a mass shooting down from four victims to three, which led to more of these shootings being tracked, but there may be earlier ones that are not included. The chart also does not include the thousands of killings each year in which there were fewer than three fatalities.

Correction: A chart in the the original version of this story misstated Kalamazoo’s location. It’s in Michigan, not Mississippi.