Played by Gordon Clapp: Medavoy is a walking bundle of neuroses disguised as a police detective. Cursed with a sometimes uncontrollable stammer and an abundance of allergies, Greg used to be the butt of a lot of jokes among the squad. However, he's a pretty good investigator and good researcher who has managed to earn the respect of his coworkers despite all his personal problems. He left his shrewish wife Marie to have an affair with Donna Abandando, but when she broke things off for good (due mostly to Greg's immaturity), Greg tried going back to his loveless marriage for the sake of his daughters. That didn't work; neither did a pursuit of attractive co-worker Abby Sullivan, who turned out to be a lesbian. Greg wound up fathering Abby's baby by artificial insemination, however, but becoming a father a third time hasn't improved his disposition much. Working with the dynamic and friendly Baldwin Jones, on the other hand, has.
Clapp largely stuck to theater after that, though he did have a small part on USA's sitcom "Check it Out!" He reteamed with Sayles as a nasty union buster in "Matewan" and a short-fused baseball player in "Eight Men Out," two roles that are a world apart from the one in which he would be cast on "NYPD Blue."
Initially signed as a guest actor for only a few appearances, Clapp, along with Gail O'Grady, proved so popular with the fans that they quickly became series regulars. Amid all the bleakness on "Blue," Clapp is usually a good source of comic relief, though Gordon occasionally gets to show off his serious side. He recently won an Emmy for the role.