The movie opens outside of a building where terrorists are holding hostages and a nuclear bomb. The Reno Sheriff's Department arrives in a helicopter to handle the situation. The main characters come off the helicopter wearing their tactical suits and carrying guns and ammo, except for Dep. Clementine Johnson (Wendi McLendon-Covey), who’s wearing a skimpy, revealing costume under a trench coat.
As the Sheriff's Department prepares for the mission, the agents overseeing the action notice their commanding officer is missing. Lt. Jim Dangle (Thomas Lennon) bursts into the scene on a motorcycle, wearing his trademark hot pants, only to crash after jumping a police car. Deputy Travis Junior (Robert Ben Garant) then wakes up and realizes it was all a dream. He realizes that he was driving, and both he and Dangle crash through a construction site into a port-a-john.
The film continues with introductory clips of the officers, telling how they became interested in law enforcement, à la COPS. After a humorous scene involving a chicken in the road miscoded as an "armed person on a roof", Lt. Dangle tells everyone that they have been invited to the American Police Convention in Miami Beach, but after the 35 hour bus ride, the group realizes their names are not on the entrance list, so they can not get their entrance passes or hotel keys. They end up booking rooms at a motel downtown, which seems to be a hub of illegal activity. That night, the police officers change into skimpy clothing and attempt to seduce one another with alcohol. As all are unsuccessful, they turn to self-pleasure. This prompts a disgusted Jones to run away, as he sees everyone through their open windows.
After everyone recovers from their hangovers (including Johnson who spends the rest of the film trying to figure out the identity of a man whose face she had tattooed on her left breast the night before), the team goes to the convention site to see if their tickets were found. When they get there they see that the entire building has been blocked off and covered because of a bio-chemical terrorist attack. The only people left outside are the HazMAT people, National Security, and assistant deputy mayor Jeff Spoder (Patton Oswalt).
The head of National Security tells the Reno Sheriffs Department that since they are the only Police officers available, they will have to provide law enforcement for all of Miami Beach. A high-ranking SWAT agent (Dwayne Johnson, a.k.a. The Rock) arrives on the scene, but he ends up blowing himself up when he tries to show the team how to handle a grenade.
The team arrives at the Miami Beach Sheriff's Department and finds that everything there is a lot better than what they have in Reno, including the squad cars; Miami Beach Sheriff Deputies ride in 2006 Mustangs instead of old Crown Victorias. The team responds to several emergency calls, which include an alligator in a swimming pool (a careless neighbor gets killed), street prostitution (which turns out to be repeat Reno offender Terry, who claims to have flown into town on his private jet to record an album), and a dead beached whale, which they decide to remove by blowing up the whale and chunks of flesh fly everywhere.
As usual, the team has a ton of fun with their antics around the city. They find out that the person who poisoned all the police officers at the convention was Jeff. His plan was to gang up with Ethan the drug lord (Paul Rudd), who pretends to be Cuban but is really from Colorado and take over Miami Beach. Jeff kills the drug lord when he is discovered and runs off with the antidote. The team chases him down on golf carts and just as they’re about to get beaten in a showdown on a bridge, Jones and Garcia show up in a Marine helicopter and the acting Mayor gives up. Lt. Dangle puts him under arrest and in a squad car when Trudy, who is in the Marine AH-1 SuperCobra helicopter, accidentally fires one of the missiles into that same squad car.
The next day, all the law enforcement officers receive the antidote. All of the officers clap and congratulate the Reno Sheriffs Department on their work done well. Lt. Dangle gets a job offer from the Aspen, Colorado Sheriff's Department (his dream job) and accepts. He tells the team that while he’s enjoyed working with them, he’s leaving.
The team is about to board the bus when Terry tells them that he’s got a jet. He offers them a ride in his jet and claims that his limo is just about to arrive to take him to the airport. No one believes him until a limo drives up to pick up Terry. In awe, they all ride with Terry in the limo to the jet and apologize for not believing him.
Back in Reno, Garcia briefs the team. The door opens, interrupting his talk, and Dangle walks up to take the briefing sheets from Garcia. Apparently, the Aspen Sheriff's Department found out Dangle was gay and have a strict policy against hiring homosexuals. Trudy goes up to Dangle, cups his private parts, and tells them that he actually came back for her. With that said, Dangle continues the briefing, revealing that the Reno Sheriffs Department has been invited the National Police Convention in Scotland Yard. The movie ends with everyone cheering.
The film stars Thomas Lennon, Ben Garant, Kerri Kenney-Silver, Cedric Yarbrough, Wendi McLendon-Covey, Niecy Nash, Carlos Alazraqui, Paul Rudd, David Koechner, and Mary Birdsong. Certain famed actors make cameos, namely Michael Ian Black (who co-starred with Lennon and Kenney in Viva Variety), Patton Oswalt (Comedian and King of Queens co-star), Danny DeVito (also one of the film's executive producers), Paul Reubens (playing a different character than he plays on the series), Nick Swardson (who appears as his show character "Terry") and Dwayne Johnson (former professional wrestler The Rock). All members of The State appear in the movie. This is the first time every member has been together on camera in quite some time.
The theme song, "Police and Thieves," is performed by Dave Grohl of the Foo Fighters. This is alluded to by Lennon, Garant, and Kenney-Silver on one of the audio commentaries, who say they are not allowed to discuss who performed the song, but say viewers should "Google it" to find the answer.
The film reprises some jokes from the original TV series for the benefit of first-time viewers, an example being Dangle's explanation for wearing shorts on the job, which was also featured in the first episode of the series.
