Custody of Prisoners
The U.S. Marshals Service is responsible for the safe and secure confinement, care and transportation of federal prisoners from the time of court-ordered custody until either their acquittal or their conviction and delivery to the Federal Bureau of Prisons to serve their sentence.
Once ordered into custody by a U.S. District Court, the U.S. Marshals Service assumes responsibility for all prisoners charged with a federal offense, regardless of which state, local or federal law enforcement agency made the arrest.