Jim Street (COLIN FARRELL) and Brian Gamble (JEREMY RENNER) are partners with L.A.'s Special Weapons and Tactics unit (S.W.A.T.) the deals with various situations too dangerous for the regular police. During a hostage standoff, they manage to save the day and the hostages, but not without breaking orders and injuring one of the hostages.
That brings the wrath of Capt. Thomas Fuller (LARRY POINDEXTER) who demotes them, prompting Gamble to quit. Street stays on, however, taking a low-profile, low-level position for the next six months until Commander Dan "Hondo" Harrelson (SAMUEL L. JACKSON) is assigned to put together a new team.
In addition to Street, he recruits and trains Deacon "Deke" Kaye (LL COOL J), Chris Sanchez (MICHELLE RODRIGUEZ), Michael Boxer (BRIAN VAN HOLT) and T.J. McCabe (JOSH CHARLES) and soon they're an efficient and successful unit, much to the dismay of Fuller. Yet, when international arms smuggler and drug dealer Alex Montel (OLIVIER MARTINEZ) shows up and takes care of family business with lethal force, it's up to the S.W.A.T. team to deal with him.