A SWAT (special weapons and tactics) team is an elite paramilitarytactical unit (准军事作战小组) in American law enforcement departments. They are trained to perform high-risk operations that fall outside of the abilities of regular officers. Their duties include performing hostage rescues and counter-terrorism operations, serving high risk arrest and search warrants, subduing barricaded suspects（镇压有阻碍的嫌疑人）, and engaging heavily-armed criminals. A SWAT team is often equipped with specialized firearms including submachine guns（自动冲锋枪）, assault rifles（突击步枪）, breaching shotguns（散弹枪）, riot control agents（控制人群用的化學劑，such as tear gas、pepper spray）, stun grenades(震憾弹)and sniper rifles(阻击步枪). They have specialized equipment including heavy body armor, ballistic shields, entry tools, armored vehicles, advanced night vision optics, and motion detectors for covertly determining the positions of hostages or hostage takers inside of an enclosed structure..

The first SWAT team was established in the Los Angeles Police Department in 1968. Since then, many American and Canadian police departments, especially in major cities and at the federal and state-levels of government, have established their own elite units under various names; these units, regardless of their official name, are referred to collectively as SWAT teams in colloquial(口语的）usage.