'Hawaii Five-0': Tom Sizemore investigates McGarrett

The plot is thickening some more on "Hawaii Five-0."

The CBS series has added Tom Sizemore ("Saving Private Ryan," "Black Hawk Down") in a recurring part for Season 2. He'll play a former Detroit homicide detective who now heads up the internal affairs division in Honolulu, EW reports -- which almost certainly means he'll be looking into some of McGarrett's (Alex O'Loughlin) and the Five-0 team's extracurricular activities.

Sizemore is the second well-known actor to join the "Five-0" cast in the past week. "Lost" alum Terry O'Quinn will also have a recurring role in the coming season as McGarrett's former Navy SEAL trainer and a friend of his dad.

Sizemore has made a bunch of independently produced/straight-to-video movies in the past couple years, but his TV work has been limited. He guested on "It's Always Sunny in Philadelphia" last year and had a recurring part on Starz's "Crash" in 2008-09 (in addition to appearing on VH1's "Celebrity Rehab"). He co-starred with Ethan Hawke in the FOX pilot "Exit Strategy" earlier this year, but the network passed on it.