List of mass shootings by death toll

A mass shooting is a violent crime in which one or more attackers use a firearm to kill or injure multiple individuals in rapid succession. There is no widely accepted specific definition, and different organizations tracking such incidents use different criteria. Mass shootings are generally characterized by the targeting (often indiscriminate) of victims in a non-combat setting, and thus the term generally excludes gang violence, shootouts, and warfare. Mass shootings may be done for personal or psychological reasons, such as by individuals who are deeply disgruntled, seeking notoriety, or are intensely angry at a perceived grievance; though they have also been used as a terrorist tactic, such as when members of an ethnic or religious minority are targeted. The perpetrator of an ongoing mass shooting may be referred to as an active shooter.