The following weapons were used in the film The Spirit:
IMI Desert Eagle Mark XIX
Smith & Wesson Model 500
The Octopus (Samuel L. Jackson) wields two monster revolvers (each with a customized barrel shroud). These started out as 4" Smith & Wesson Model 500s. According to a source close to the armorer who built the guns for the film, the barrel shrouds were made from matching brushed satin stainless steel and the cylinders were re-machined.
Phobos, etc. are often seen wielding Intratec TEC-9.
This belongs in the category of "Maybe" but some members of the SWAT team appear to be carrying Steyr AUG assault rifles, as well as other small/compact and as of yet unidentified weapons.
Quad 12 gauge "handguns"
A rather unconventional pair of 'Quad guns' comprising two sets of short barreled shotguns per weapon, are used by the Octopus in the trailer. The Octopus mentions when wielding these weapons that he likes to use "eight of everything". A source close to the armorer who worked on the movie has informed IMFDB that the weapons were built from scratch as non-functional props and that the muzzle flash was added in post-production.
Sand Saref spins a revolver, which appears to be a M1917 Revolver .45 acp Revolver, or its predecessor, the S&W .44 Hand Ejector Model.
Smith & Wesson Model 19
The more traditionally uniformed police officers appear to carry Smith & Wesson Model 19 revolvers.
Beretta 950 Jetfire
Combo Assault Rifles .aka 'The Darrow'
The Octopus also dual-wields two giant assault rifles which are in reality a pair of a cluster of weapons 'glued' to each other. The weapons are a bunch of obviously plastic Airsoft guns attached together (obvious for several reasons, sharped eyed viewers can tell the difference between Spring Airsoft guns and the real deal, and it would be impossible for the actor to wield eight live weapons due the weight). A single cluster of weapons appears (for now) to be two M4 style carbines attached to each other as well as a Spring model M11 with fake suppressor and an Airsoft H&K UMP (with a fake suppressor standing in for a shotgun barrel) (along with a plethora of Aimpoint sights, rails, foregrips, flashlights as well as some obvious 12 gauge shell holders on the sides). There is also a SPAS 12 on each of them, the correct name for the combi gun is the Darrow named after comic artist Geoff Darrow who always used to draw hyper detailed multi barrelled combi guns on his characters. He wields a cluster as mentioned above ... in each hand!
Unknown Police Shotguns
Several Police officers wield unknown shotguns with Surefire Flashlight Fore ends. One Female officer wields a heavily customized shotgun with a ridiculous array of sights, flashlights and other gadgets attached.
Dual Short barreled O/U Shotguns
The Octopus also wields two short-barreled O/U shotguns, which were built from the CZ Redhead 12-gauge, according to a source close to the movie's armorer.
Fake Five barreled auto cannons
Strictly fictional five barreled 'nordenfelt' type autocannons for the Apache helicopters. The middle gun appears to represent the 'real world' 30mm M230 Chain Gun, whereas the smaller surrounding guns are for a smaller caliber. Since the main gun is supposed to be the 30mm M230 Chain Gun (as seen on the real world AH-64 helicopters), and this may be a fantasy upgrade for that weapons system.