SWAT team
A SWAT team is a squad of police officers, who are especially trained and equipped to engage heavily armed suspects. Elements of their training and equipment is identical to, or similar to, that used by soldiers.
Triggers for the creation of SWAT teams
Police departments didn't employ SWAT teams until certain incidents highlighted their necessity. One instance was an 1966 incident on The University of Texas at Austin, when Charles Whitman took multiple weapons, including an M-1 rifle, up the campus 18-storey clock tower, where he was able to overlook much of the campus, and opened fire, killing 18 people, and wounding many others.
The officers on the scene did not have any equivalent weapons. Nor had they ever had any training in dealing with heavily armed threats. Nevertheless Houston McCoy and Ramiro Martinez climbed the tower, intending to try to subdue Whitman. McCoy carried a shotgun, while Martinez was only armed with he service pistol, while Whitman's M-1 was a military style weapon, which fired high-powered bullets that were fatal at over 1,000 metres, and which used a bullet clip with 8 bullets, that could be rapidly fired, one after another.
McCoy described rounding a corner, and seeing Whitman, who saw them. The weapons he and Ramirez carried would only be accurate and close range, while Whitman could have picked them off at a distance. McCoy thought that the only reason they were able to get close to Whitman was that he wanted them to shoot him. Whitman's death is described as an early incident of what is now called "suicide by cop".
Equipment
Officers on SWAT teams are trained in a variety of weapons, including sniper rifles, regular assault rifles, submachine guns, and the use of shotguns loaded with special munitions, like door breachin hatton rounds, and "flash bang" grenades. . They are regularly found wearing military style helmets and body armour.