In the United States, a SWAT team (special weapons and tactics, originally special weapons assault team) is a police tactical unit that uses specialized or military equipment and tactics. Although they were first created in the 1960s to handle riot control or violent confrontations with criminals, the number and usage of SWAT teams increased in the 1980s and 1990s during the War on Drugs and later in the aftermath of the September 11 attacks. In the United States by 2005, SWAT teams were deployed 50,000 times every year, almost 80% of the time to serve search warrants, most often for narcotics. By 2015 that number had increased to nearly 80,000 times a year. SWAT teams are increasingly equipped with military-type hardware and trained to deploy against threats of terrorism, for crowd control, hostage taking, and in situations beyond the capabilities of ordinary law enforcement, sometimes deemed "high-risk".

SWAT units are often equipped with automatic and specialized firearms, including assault rifles, submachine guns, riot shotguns, sniper rifles, riot guns, riot control agents, smoke grenades, stun grenades, and stinger grenades. In addition, they may use specialized equipment including body armor, ballistic shields, entry tools, armored vehicles, thermal and night-vision devices, fiberscope cameras, and motion detectors for covertly determining the positions of suspects inside enclosed structures.