SWAT duties include:
- Hostage rescue.
- Crime suppression.
- Perimeter security against snipers for visiting dignitaries.
- Providing superior assault firepower in certain situations, e.g. barricaded suspects.
- Rescuing officers and citizens captured or endangered by gunfire.
- Countering terrorist operations in cities.
- Resolving high-risk situations with a minimum loss of life, injury, or property damage.
- Resolving situations involving barricaded subjects (specifically covered by a Hostage Barricade Team).
- Stabilizing situations involving high-risk suicidal subjects.
- Providing assistance on drug raids, arrest warrants, and search warrants.
- Providing additional security at special events.
- Stabilizing dangerous situations dealing with violent criminals (such as rapists, serial killers or gangs).
- Armed patrols
Source: Wikipedia