The following weapons were used in the film Conspiracy Theory:
The Glock 17 is used by Dr. Jonas (Patrick Stewart) as well as other characters in the film. A few Glock 17's can also be seen being carried by N.Y.P.D. officers in a few scenes. At the climax of the film, Alice Sutton (Julia Roberts) uses a Glock 17.
Smith & Wesson 645
When Jerry is subdued at the Department of Justice Building, an officer of the Federal Protective Service can be seen armed with a Smith & Wesson 645. The officer then is forced to drop it when Jerry manages to grab his partner's sidearm, forcing a temporary standoff until Alice talks him down.
Smith & Wesson 5946
Officers of the Federal Protective Service can be seen armed with Smith & Wesson 5946 pistols as their sidearms, mainly at the Justice Department. When the officers try to remove Jerry from the building, Jerry grabs one of these pistols out of an officer's holster and forces the other officers to drop their weapons.
Government agents posing as FBI including Agent Lowry (Cylk Cozart) can be seen carrying SIG-Sauer P226 pistols as their sidearms. At one point, Jerry confronts Agent Lowry in his car while Lowry and his partner are conducting a stakeout outside Alice's apartment, Jerry holding his partner's P226 on him, having taken it off him after having knocked him out off-screen. He then relieves Lowry of his P226 as he interrogates him, then uses one of the pistols to hit him on the back of the head to knock him out, having to hit him twice before succeeding in rendering Lowry unconscious.
Colt Officer's ACP
At one point, Alice and Lowry go to the Criminal Courts building looking for Jonas. While there, Alice gets Lowry alone and pulls a Colt Officer's ACP on him, interrogating him as to who he really was. Once she finishes the interrogation, she too pistol-whips Lowry on the back of the head to knock him out, though isn't as effective as Jerry as Lowry recovers almost immediately after she leaves.
Smith & Wesson Model 15
Smith & Wesson Model 60
Colt AR-15A2 Government Carbine
At one point in the film, Jerry takes Alice to the farm where Alice's father was killed, the two being ambushed by Jonas and his men, including a sniper (John Schwartzman, the film's cinematographer) who is armed with a Colt AR-15A2 government carbine with a 20-round magazine, night-vision scope on the carry handle, and a laser sight. He tries to use the weapon to shoot Alice in the back of the head as she's fleeing, but accidentally shoots one of his own comrades instead when he steps into the line of fire just as the sniper fires the fatal shot.
DefTech 1315 Gas Gun
At one point in the film, Jonas' men attempt to raid Jerry's apartment, firing tear gas grenades through the window from a balcony across the street using DefTech 1315 gas gun launchers.
Model 7290 Flashbang Grenade
During the raid on Jerry's apartment, one of Jonas' men tosses a Model 7290 flashbang grenade through a broken window.