Final answer:
The US government defines an active shooter as an individual actively engaged in killing or attempting to kill people in a populated area. This definition is used in the context of tragic events that have spurred ongoing debates about gun control laws and access to firearms.
Step-by-step explanation:
The agreed-upon definition of an active shooter by US Government Agencies, such as the Occupational Safety & Health Administration (OSHA), describes an individual actively engaged in killing or attempting to kill people in a populated area. In cases like the tragedy at the Covenant School in Nashville in March 2023, where a gunman took several lives, or historical incidents such as the shootings at Columbine and Sandy Hook Elementary, these perpetrators meet the criteria of active shooters. These tragic events underline the broader debates about gun control laws, mental health issues, and the easy accessibility of firearms in the United States. As these discussions continue, government agencies attempt to balance public safety with the constitutional rights afforded to citizens, often leading to varying degrees of legislation at state and federal levels.