found: Mass murder with firearms, July 2015:executive summary (for the purposes of this report, "mass shooting" is defined as a multiple homicide incident in which four or more victims are murdered with firearms, within one event, and in one or more locations in close proximity. Similarly, a "mass public shooting" is defined to mean a multiple homicide incident in which four or more victims are murdered with firearms, within one event, in at least one or more public locations, such as, a workplace, school, restaurant, house of worship, neighborhood, or other public setting)
found: Segens medical dictionary, 2012:mass shooting (the discharging of firearms multiple times by one or more parties into a group of unarmed victims)
found: McGraw-Hill concise dictionary of modern medicine, 2002:mass shooting (Multiple discharging of firearm(s) into a group of unarmed victims)
found: Here's why no one can agree on the number of mass shootings, in New Republic, Oct. 3, 2015:(The confusion stems from varying governmental categorizations. There are mass murders and mass killings, active shooters and serial killers, mass shootings and mass public shootings. For instance, Mass Shooting Tracker, a crowd-sourced website that many news outlets use, defines a mass shooting as one with "four or more people shot in one event." In other words, they include incidents in which four people are wounded, but no one is killed.)
