U.S. Marshal officers are most visible in Las Vegas's federal courthouse. Officers patrol the entrance, screen visitors, and manage security. There is usually an officer in each courtroom while court is in session. And their purpose is to protect the federal judges as well as jurors, witnesses, attorneys, prisoners, clerks, and the public. n But the USMS is active behind the scenes as well. They search for and apprehend fugitives. They run the Witness Security Program (which protects endangered witnesses in federal cases). They transport federal prisoners through the Justice Prisoner and Alien Transportation System (JPATS). And they manage and sell assets that were seized through criminal activity.