The most commonly seen gun in the film, the Colt Detective Special snubnose revolver is carried by both Officer Bud White (Russell Crowe) and Lt. Ed Exley (Guy Pearce). Det. Sgt. Richard Stensland (Graham Beckel) also carries one of these, seen only when he hands it over to his superiors.
Sgt. Jack Vincennes (Kevin Spacey) carries a Colt Commander with customized grips as his duty sidearm, carrying it during the "Movie Premiere Pot Bust" and while arresting the Nite Owl suspects.
Exley tells Capt. Smith that the cook grabbed a .38 caliber revolver but was murdered before he could use it. From looking at the revolver and the grips the revolver can be identified as a Colt revolver. It appears to have the rounded grips that the company went to in the mid-1930's and the exposed ejector rod that was a Colt signature until the late sixties. It's a Colt Official Police as the frame size is too large to be a Police Positive and the grip size too large to be a Pocket Positive.
Almost as commonly seen as the Colt Detective Special, several LAPD officers carry the 12-gauge Ithaca 37. The Nite Owl shooters were said to have used 12-gauge pump shotguns with a five-shell capacity. Breuning (Tomas Arana), Carlisle, Exley, and White are among the officers seen using this shotgun throughout the film. Carlisle and Exley carry these during the Bunker Hill apartment raid, leading to Exley's "Shotgun Ed" moniker. At the Victory Motel shootout finale, Bud White uses the shotgun with great effect before Exley grabs it and uses it to ultimately shoot Dudley Smith.
Roland Navarette (Steven Lambert) shoots Officer Carlisle (Michael McCleery) with a M1911A1 when Exley and Carlisle bust in their hideout to arrest the Nite Owl suspects after they escaped. White gets one from his car, giving it and an extra magazine to Exley to use during the final gunfight at the Victory Motel.
Capt. Dudley Smith (James Cromwell) appears to be using a Smith & Wesson Model 15 Combat Masterpiece with a 4" barrel during the climactic shootout at the Victory Motel between the corrupt officers, Ed Exley and Bud White.
