Donnie WahlbergDetective Joel Stevens Neal McDonoughAssistant District Attorney David McNorris Mykelti WilliamsonPolice Department Detective II Bobby 'Fearless' Smith Gary BasarabaPolice Department Police Officer III Ray Hechler Lana ParrillaTeresa Ortiz, paramedic in season one, rookie police officer in season two Jason GedrickPolice Department Police Officer II Tom Turcotte Nina GarbirasAndrea Little, a reporter (season one) Vanessa WilliamsDetective Katherine Pierce Dorian HarewoodCaptain Ronald Hicks Kelly RowanMarian McNorris Rick GomezDetective Daniel Ramos Chase EllisonWillie Stevens Matt CravenDr. Michael Hirsch David ProvalPaul Turcotte Rino RomanoPaul Turcotte in 1976 Wendy SchaalDarlene Beechem Derek HamiltonJimmy Black John KapelosHugo Pinkston Kathleen WilhoiteSally McBride Daniel ZacapaCarlos Ramirez Stacy KeachJack 'Mac' McNorris Virginia MadsenErika Ashland Cody KaschTrevor 'T.J.' Jankowski Jr. Shannon SturgesCherie Hechler Beau BillingsleaPolice Academy Commandant Tyler ChristopherHolden McKay Alimi BallardYoung Marvin Lloyd Jennifer SkyVanessa Griggs / Laura Sheeri RappaportJanice Edwards Arlen EscarpetaCantrel LaFontaine Christian CamargoBradley Dawson Miguel A. Núñez Jr.Freaktown Rick RavanelloSean Dornan Trent CameronBernie Leonard Howard HessemanMel Castle Erin DanielsOfficer Karen Crane Stephen MachtJohn Donadoni Ken DavitianJewelry Store Owner Michael MuhneyChris Griggs Ernie GrunwaldCharlie Graham Jessica LundyVivian Colson Robert WisdomChronic (Daryl C. Norcott) Fran BennettBeatrice Rahming Michael Paul ChanLobo Chan Ramón FrancoLuis Valdoriso Tommy HinkleyMr. Flannery Jason GeorgeThomas Paltrow Doug HutchisonWally Pollard Christopher GorhamGordon Sinclair Fredric LehneReggie Flood Silas Weir MitchellErik Sorenson Dempsey PappionYoung Greg Haymer Neil Patrick HarrisPeter Corman David DunardIrate Grandfather Frank John HughesOfficer Vincent Manzani Patricia WettigNora Jean Flannery Garikayi MutambirwaFriend #2 Michael DempseyRecovering drunk Anthony MontgomeryRecruit Dwight Baker Richard ErdmanKevin's Dad Christopher KriesaWarden Frank Collins Chris MulkeyKevin Van Horn Cullen DouglasArnold Rabjohn Dakota FloeterYoung Wally Pollard Henry G. SandersPolice Sergeant Miller Salvator XuerebJohn McBride Ryan StockstadParamedic (uncredited) Gregory WhiteJudge Harold Denby Robert TreborKeith (uncredited) Jon AvnetDirector / Productor Michael W. WatkinsDirector Graham YostEscritor / Productor Javier Grillo-MarxuachEscritor / Productor Craig KuehneVisual Effects 
