Courtney B Vance

He was temporarily a few times during Season 6 and 7, but they realized the show didn't really need a D.A. because there was hardly any courtroom drama scenes. The show relied more on the police investigation. This was heavily clear during those first five seasons. Most of the time, you never saw Carver that active in the courtroom. He was always at the station dealing with the detectives while they were investigating or going places with them while handling a suspect. He was rather a wasted character.