Alex O'Loughlin stars as Detective Steve McGarrett, a decorated Naval officer turned cop who returns to Oahu to investigate his father's murder and stays after Hawaii's governor persuades him to head up the new team.
Masi Oka debuts in the fourth episode as the coroner and is billed as a guest star. But with the body count expected to spike considerably in Oahu, this coroner could potentially be busy for several seasons.
The original king of comedy D.L. Hughley will also guest star in Hawaii Five-0's third episode as a character named Skeet. Skeet is described to me as an inmate serving a double life sentence who challenges McGarrett to a game of hoops.