Glossary and key terms

See the glossary for definition of mass killing.

References to incidents and attacks are used throughout this report to indicate an active shooter situation.

this report, civilians refer to individuals who are neither law enforcement officers nor security personnel. Members of the military are included as civilians unless they are armed military police or federally deputized members of the National Guard.

ACTIVE SHOOTER ATTACK PREVENTION AND PREPAREDNESS (ASAPP): an options-based training platform that provides civilians with resources to develop plans and responses for an active shooter attack AVERTED ATTACK: refers to a situation where a potential attack was prevented based on tips and observations CIVILIAN INTERVENTION: instances where individuals who are not law enforcement or security personnel intervened or attempted to intervene to end an active shooter incident IMPROVISED EXPLOSIVE DEVICE (IED): a device placed or fabricated in an improvised manner, incorporating destructive, lethal, noxious, pyrotechnic, or incendiary chemicals, designed to destroy, incapacitate, injure, harass, or distract

INSIDER THREAT: an employee, contractor, student, or other individual with legitimate access and/or trust who carries out an active shooter attack LAW ENFORCEMENT EXCHANGE: instances where both the shooter and law enforcement officer(s) discharge firearms at each other

MASS KILLING: three or more individuals killed in a single incident not including the shooter MASS SHOOTING: three or more individuals injured and/or killed in a single incident not including the shooter MULTIPLE LOCATIONS: incidents where an active shooting attack occurred at more than one location PREDATORY BEHAVIOR: incidents when a perpetrator considers, plans, and prepares for the act of violence; they are preceded by observable warning sign behaviors that, if recognized and reported, can provide opportunities for disruption SECURITY INTERVENTION: instances where security personnel intervened or attempted to intervene to end an active shooter incident

SECURITY PERSONNEL: employee(s) or volunteer(s) who protects a building or property but has no sworn law enforcement authority

SHOOTER CONNECTION: refers to the relationship or link between the shooter and the location, victims, or circumstances of the incident 52 Refer to Appendix

As defined by the FBI’s Weapons of Mass Destruction Directorate and the FBI’s Laboratory Division