Welcome to Law & Order: Casino Victims Unit, where Dennis Quaid is suitably squinty, frowny and be-cowboy-hatted as real-life former Vegas sheriff Ralph Lamb, a no-guff-takin' rancher who uses his fists to express his displeasure with Vegas's growth, and the effect it's having on his ranchin' and non-nonsense-talkin' business. His chief complaint right now is the ever-more-frequent planes landing right over his cattle trail, instead of coming in from the east as he was promised, and he brawls with some airport suits and winds up in the back of a police car, before being deputized by the law and order mayor Ted Bennett (the always reliably gruff Michael O'Neill) to find the murderer of the governor's daughter, what with the real sheriff being MIA.
Lamb's airport dustup is witnessed by one Vincent Savino, a Chicago mobster arriving to plant his own flag in town, and first order of business is find out why the newly opened Savoy is leaking money. There's a problem somewhere in the casino, and Savino's going to find it, with his eye for detail, like a dealer with a chip stashed under his watch and a vase of flowers that blocks the casino's security system. He also beats up a flunky who laid hands on a dealer without permission. The parallels being drawn of the two men being not-so-different -- they're going to clean up their respective worlds -- aren't exactly subtle.
The district attorney spits fire over the mayor's appointment of Lamb -- who enlists the aid of his brother Jack (Jason Mara, who might be relieved to not be running from dinosaurs in Terra Nova) and his son, who seems more capable of banging married women and getting shot at by angry husbands than police work. The ADA, and love interest, Katherine O'Connell (Carrie-Anne Moss), is less worried about it, mainly because she doesn't appear to be working for Savino and the mob like the DA is. The mayor's not just missing; he's hiding from the mob, which is under the impression that he's been spilling secrets to the Gaming Commission. The sheriff knows where the bodies are buried, and then he becomes one, after the DA sells him out, turning him over to Savino and his men, while hinting at a vision of a future Vegas with even more money lining criminal pockets.
Actually, scratch that -- The sheriff's not a buried body, because Savino and his guys just kill him and leave him in the desert. You'd think hiding the body and avoiding the attention a sheriff's murder would bring would be the smart thing to do, especially since Savino is so keen to protect his crooked interests, but we do need a dramatic way for Lamb to get promoted to Actual Sheriff instead of Deputy Who Just Signed Up To Get Air Traffic Routing Consideration.