Special agent (United States)

In the United States, a special agent is usually a detective or investigator for a state, county, municipal, federal, or tribal government who primarily serve in investigatory roles. Within the United States' federal law enforcement system, dozens of federal agencies employ federal law enforcement officers, each with different criteria pertaining to the use of the titles "Special Agent" versus "Agent". In intelligence usage, agent refers to one who is recruited, trained, controlled and employed to obtain and report information.

In general, some, but not all, agents are federal law enforcement officers, and hold either arrest authority or the right to conduct minor criminal/non-criminal investigations. In some agencies, however, an agent can have both arrest and minor criminal/non-criminal investigatory authority, yet still have no authority to conduct major criminal investigations. On the other hand, nearly all special agents are federal law enforcement officers, are distinctly empowered to conduct both major and minor criminal investigations, and hold arrest authority. Most special agents are authorized to carry firearms both on and off-duty, whereas only some agents are authorized to do so.

Uniquely, many American railroad police departments utilize "Special Agent" as either a rank or title, even if the special agent's role is not primarily investigatory in nature.

Within the U.S. government, the title of special agent designates a general investigator in GS-1810 job series, federal criminal investigator in the GS-1811, Diplomatic Security Service FS-2501 job series, or a counterintelligence operations specialist in the GS-0132 job series according to the Office of Personnel Management (OPM) handbook. Special Agents typically have an undergraduate degree. They are usually empowered to carry firearms, make arrests, and investigate violations of federal laws. The titles of "Agent", "Investigator", and "Background Investigator" refer to all other 1800 series job series designations, including:

Although some federal agencies have recently defined certain background investigators and other non-1811 personnel as "special agents", this is purely an administrative title with a different meaning, and does not confer actual Special Agent status on them. Although some 1810-series investigators are empowered in some circumstances to carry firearms and investigate crimes, they are not empowered to make arrests. In general, arrest authority is what distinguishes a traditional Special Agent (1811) from most other 1800 series personnel. There are exceptions: some 1800 series positions, such as Border Patrol Agents, Federal Air Marshals and Secret Service Uniformed Division Officers have the authority to enforce federal law, and thus have arrest authority. However, unlike the 1811 Criminal Investigators, or Special Agents, they do not have the authority to conduct major criminal investigations. In general, non-1811 personnel who wear a badge and a gun and have arrest authority are considered "Agents", while Criminal Investigators who carry a badge, gun, and credentials and have arrest authority are considered "Special Agents". All other 1800 personnel who conduct investigations (background or otherwise) and who do not have arrest authority are "Investigators", "Background Investigators", or "Compliance Officers", no matter what their administrative title might be.

...
Wikipedia