Dr. Sheldon (first name unknown) is a specialist in mechanical engineering working with New York City parole boards to maintain and improve their ankle tracking systems. He consulted with detectives on Bennie Edgar Ralsey, a released serial rapist suspected in the brutal assault of his therapist, Dr. Greta Heints.
Ralsey was shown resisting temptation from danger zones but never crossing the line on the office's monitor on screen. But one night, Ralsey was fed up with suspicion and placed the tracker on his cat before running. Ralsey was never guilty of Heints' assault, but was still institutionalized for parole violation nevertheless. (SVU: "Mother")