Which federal agency is responsible for witness security?

The U.S. Marshals Service (USMS) is indeed the federal agency responsible for witness security. The Witness Security Program, often referred to as WITSEC, was established to protect witnesses who are at risk of retaliation due to their cooperation with law enforcement in prosecutions. This program offers a variety of protective measures, including relocation and new identities for witnesses and their families, ensuring their safety.

While the FBI does play a role in investigating crimes and supporting witness protection efforts, it does not administer the Witness Security Program. The Department of Homeland Security (DHS) focuses on broader issues of national security and immigration, so it is not directly involved in witness protection. Similarly, the Secret Service primarily protects high-profile individuals, such as the President and visiting foreign dignitaries, and does not handle the witness security program. Thus, the USMS stands out as the agency specifically designated for witness security responsibilities.