Actually it is the “United States Marshal Service, Air Operations Division” based at Oklahoma City Will Rogers World airport.
They are not hiring any pilots at the present time. The last I heard they have a long list of pilot applications on file. However once hiring starts, if it ever does, they tend to ignore the old applications and just go with the new applications. Because it is a Civil Service position ex-military pilots do receive priority due to the point system.
The pilots with the Air Operations Division are a full mixture of civilian, ex-military, ex-FAA and ex-airline pilots.
I was with them for ten years until I escaped back to sanity. In the ten years I was there I flew over 9,700 hours. 70% was in the Boeing 727, 25% in the Sabre 80 and the other 5% was in Lear Jets, Westwinds and KingAir 200s. Oh yes, when you were not flying you had to be in the office from 08:00 until 16:30. Which was a lot of fun when you had just landed at 03:00 that morning after a 20+ hour crew duty day.
The government owned 727s that I flew have been parked and they are now flying lease 727s. There are rumors that they are getting Boeing 737-800 airplanes next year, but don’t hold your breath.