Second generation Glock 17 pistols are used by the members of the FBI, most notably Charlie Francis. Francis demonstrates truly poor weapon handling at one point, positioning the thumb of his left hand on top of the slide.
A Glock 19 is Phillip Broyles sidearm, although he rarely uses it. It is also seen very briefly in the hands of NYPD in one episode, and by Mitchell Lobe before he is disarmed and taken into custody.
Olivia Dunham's sidearm is a sub-compact Glock 26, 9mm. The same sidearm is also used by Nick Lane, who has an emotional connection with Dunham, likely prompting use of the same firearm.
A pair of .50AE Desert Eagles in chrome are requisitioned by Agent Dunham to kill the monster. Walter requests .50 caliber incendiary rounds in order to kill the creature, probably meaning a .50 caliber machine gun. Walter is surprisingly the one to kill the monster with two shots from his Desert Eagle. In the next shot, we can see that the gun has jammed after those two shots.
Mitchell Lobe uses a black, suppressed Kahr K9 9mm to execute the member of his bank robbery team who gets stuck in the vault; the Kahr is never seen with the slide forward, even when "fired." Mitchell's wife Samantha retrieves his Kahr K9 in stainless from a closet in order to try to kill Agent Dunham. Mitchell seems to have a thing for the K9.
