"Indeed, the AR-15 is also inextricably linked to tragedy. Mass shootings are central to the gun’s narrative, and its popularity.... It is unclear when and how the rifle worked its way into the United States’ lexicon of violent crimes. In 1982, George E. Banks shot to death 13 people with the weapon, and in 1997, an AR-15, among other semiautomatic military-style rifles, was used in the North Hollywood shootout, a daytime robbery in California that devolved into a nearly hourlong firefight and was televised live across the country. During the gun battle, police officers were forced to run to a local gun store and take rifles to try to contend with the robbers’ firepower and body armor. Afterward, police departments around the country started making AR-15s standard issue for officers."
January 1, 1970
https://en.wikiquote.org/wiki/AR-15_style_rifle