
In the United States, a special agent is a detective or investigator who investigates suspected violations of federal, state or local laws. Special agents may also carry firearms and make arrests. Special agents work for many different law enforcement agencies. In some agencies, only special agents may carry firearms. An example is special agents in the Internal Revenue Service. To become special agents most applicants must pass written and physical examinations. In the FBI, like many agencies, applicants must go through a background check.
Congress was the first to use the title in 1801 when they changed the name of U.S.Post office "surveyors" to "special agents". In 1880, the U.S. Congress created the position of "Chief Postal Inspector" and renamed these special agents to postal inspectors.
The following US federal agencies use special agents:
State level: