Quote:The agreed-upon definition of an active shooter by U.S. government agencies—including the White House, U.S. Department of Justice/FBI, U.S. Department of Education, and U.S. Department of Homeland Security/Federal Emergency Management Agency—is “an individual actively engaged in killing or attempting to kill people in a confined and populated area.”

Implicit in this definition is that the subject’s criminal actions involve the
use of firearms.

For purposes of its study, the FBI extended this definition to include individuals, because some incidents involved two or more shooters. Though the federal definition includes the word “confined,” the FBI excluded this word in its study, as the term confined could omit incidents that occurred outside a building.