United States Marshals Service

Primary duties

• Judicial security: Protecting judges, jurors and court staff, and securing federal courthouses; the Service provides protective details for threatened judicial officers such as judges.
• Fugitive operations: Locating and apprehending fugitives sought on federal and often state warrants; marshals specialize in tracking and arresting individuals wanted by the justice system.
• Process and arrests: Serving subpoenas, civil process and executing arrest procedures as required by federal law, including serving warrants.
• Prisoner transport: Managing secure movement of persons in federal custody and overseeing the logistics of detention transport across districts.
• Witness protection: Operating the Witness Security Program (WITSEC), which protects vulnerable witnesses and their families when their safety is at risk.
• Asset forfeiture and court order enforcement: Seizing assets tied to criminal activity and enforcing court judgments.

USMS organization is district-based, with marshals assigned to the federal judicial districts that cover the United States. The Service maintains specialized units for fugitive pursuit, tactical operations, and coordination of long-distance prisoner movement. It often works alongside other federal agencies when investigations or operations overlap with broader national priorities handled by organizations such as the FBI, including cases that touch on organized crime or national security concerns.

History and development

Since its establishment in the late 18th century, the Marshals Service has adapted from serving writs and supporting the early federal court system to running complex national programs. Over time its responsibilities expanded to include formal witness protection, centralized prisoner transportation, and coordinated fugitive task forces that combine federal, state and local resources.

The Service is distinctive for its close connection to the federal courts and for roles that emphasize custody, security and enforcement of court orders rather than broad investigative mandates. That division of labor helps clarify when the U.S. Marshals will lead an operation and when investigative agencies will take primary responsibility.

Because much of its work is operational—ensuring people, evidence and court proceedings are safe and enforceable—the USMS is an essential but often less-publicly visible component of the federal justice system. Its duties keep courtroom functions secure, bring fugitives to justice, protect witnesses whose testimony is critical to prosecutions, and enforce the physical orders of the courts.

For more information about specific programs, procedures and local field offices, see official resources and the Service's public materials. Federal court procedures, protection details for judges, processes for serving arrest documents, and the execution of warrants are regularly coordinated through the Marshals, often in cooperation with agencies such as the FBI on matters like investigations into organized crime.