He hasn't because he's legally blind. He can barely see the shape of the hand in front of his face
see my tagline
The judges abuse the Marshals, use them as chauffeurs and errand boys, and often ignore Marshals' recommendations to keep prisoners in handcuffs when they appear before Federal Judges. The judges often show little regard for the judgment of the Marshals, who know the behavior of the violent offenders whom they have tracked and apprehended much better than the judges do.
The Marshals also have a significantly higher rate of actually finding their suspects than the FBI - they are the unsung heros of the law enforcement world. The FBI usually takes credit for the finds the Marshals have made - a good example is the DC sniper case. FBI took credit, but a US Marshal who spent four sleepless nights on a computer actually tracked a vehicle down that everyone else had ignored and was able to issue the BOLO which lead to the snipers' apprehensions.
INS agent seized Elian Gonzales.
He hasn't because he's legally blind. He can barely see the shape of the hand in front of his face
How, then, can he assess the credibility of witnesses before him?