Things have changed over the last 100 years and due to the rise of acts of terrorism and the easy access to high-powered weapons ; special weapons and tactics teams have been implemented and are being utilized across the nation . The 1960s to 1990s , encounters with the sophisticated weapons of narcotics trafficking groups such as the Medellín Cartel and street gangs such as the Gangster Disciples , with organized , violent left-wing protesters at such events as the 1968 Democratic National Convention in Chicago and the 1999 WTO Conference in Seattle , with urban riots such as the 1965 Watts riots in Los Angeles and the 1967 Detroit Riot in Detroit led law enforcement to reconsider their standard side arms . As well , law enforcement experience with arsonists such as Earth Liberation Front ( ELF ) , with mass shootings and/or shootouts such as the 1984 McDonald 's massacre in San Ysidro and the 1986 shootout between eight FBI agents and two serial bank robbers in Miami ( in which the agents were out-gunned by the robbers ) and with explosive devices used by the Weather Underground , Timothy McVeigh , and Ted Kaczynski ( the " Unabomber " ) , highlighted the inadequacy of many law enforcement agencies ' weapons and tactics
McDonald 's massacre
San Ysidro McDonald's massacre
Militarization of police