Mass shootings are incidents involving multiple victims of firearm related violence. Definitions vary, with no single, broadly accepted definition. One definition is an act of public firearm violence—excluding gang killings, domestic violence, or terrorist acts sponsored by an organization—in which a shooter kills at least four victims. Using this definition, a 2016 study found that nearly one-third of the world's public mass shootings between 1966 and 2012 occurred in the United States. In 2017, The New York Times recorded the same total of mass shootings for that span of years.