The Beretta 92FS appears in the series for the most part as the service pistol for members of the Los Angeles Police Department. Several criminals are seen armed with the handgun in the series as well.
A stainless steel Beretta 92FS Compact is used by drug smuggler Victor Morelos (Gonzalo Menendez) in Season 3's "Pandora's Box" (S03E19) to threaten an informant.
A stainless steel Desert Eagle is used by Kilo in Season 4's "Pay to Play" (S04E17). Buck Winters picks up what is described as a 50 caliber Desert Eagle in "Arrow of Time" (S05E11).
The Glock 19 is the sidearm carried by various FBI Agents in the series. Special Agent Don Eppes (Rob Morrow) has a Glock 19 holstered in Season 6's series finale "Cause and Effect" (S6E16), where it is stolen and used in a series of vilgilante murders.
FBI Special Agent Don Eppes' (Rob Morrow) and FBI Special Agent David Sinclair (Alimi Ballard) both carry Glock 23's as their sidearms. If you look carefully in the episodes the slide is too short and so is the frame. Also in Season 4 episode 4 during the standoff in the elevator it is clearly marked as a Glock 23.
Special Agent Rachel Willons (Teri Polo) of the California Bureau of Investigation is armed with a two-tone Heckler & Koch USP in Season 3's "Nine Wives" (S03E12).
FBI Special Agent Colby Granger's initial service weapon is a SIG-Sauer P226 before changing to the Springfield Armory Custom TRP and then finally to the Smith & Wesson PC 945.
Special Agent Ian Edgerton (Lou Diamond Phillips) carries a SIG-Sauer P228 as his service pistol. Special Agent Nikki Davis (Sandra Lindquist) of the BATF commits suicide with her P228 in the episode "Guns and Roses".
FBI Special Agent Colby Granger switches to a Smith & Wesson PC 945 with a two tone slide. Agent Granger switched to this pistol in season 5 episode "Trouble in Chinatown" using it to gun down a shooter while waiting on his takeout food with Agent Sinclair. Possibly a personal side arm.
FBI Special Agent Colby Granger's main service pistol is a .45 ACP Springfield Armory Tactical Response Pistol, which indicates he is SWAT/HRT (Hostage Rescue Team) qualified, since only SWAT/HRT qualified FBI agents are authorized to carry that weapon on duty.
A Ruger Single Six with adjustable sights is used by disgruntled rancher Bob McHugh (Connor Trinneer) in Season 2's "Toxin" (S02E09). Analyzing the other frames of the current and proceeding scene, the weapon has a nickel or similar finish with wood grips.
Used by Ella Pierce in S04E08 to fire on FBI agents. Unsure whether this is true Glock 18C or converted Glock 17 as there is no clear view of the slide.
Several Heckler & Koch MP5A2's, fitted with Surefire dedicated forend weaponlights, appear being used by several FBI Special Agents in tactical gear before the switch to the MP5A3 w/RIS described below.
Several Heckler & Koch MP5A3's appear being used by several FBI Special Agents in tactical gear and private security guards. The Agents' MP5A3's are fitted with RIS handguards mounting vertical foregrips & Surefire Universal weaponlights. Davis can be seen using one that also features a UMP-style folding stock.
A Steyr SPP is used by counterfeiters/armed robbers in S01E07 and a Chinese thug in S05E13. It is modified to fire full-automatic in lieu of using the Steyr TMP.
One of the members of the robbery crew known as the Charm School Boys uses the Serbu Super Shorty shotgun in Season 1's "Uncertainty Principle" (S01E02).
The AR-15 carbine rifle is used by a kidnapper to provide sniper fire against the FBI in Season 3's "One Hour" (S03E17). It is mocked up to look like a Colt Model 945/KAC SR-25.
The Colt Model 977 is commonly referred to as the M4A1 carbine. It can be seen being used by FBI/FBI SWAT agents in tactical situations, fitted with various accessories such as RIS foregrips, Surefire Universal weaponlights, and C-More & EOTech red dot sights.
A Heckler & Koch G36C fitted with a RIS foregrip is used by an Asian gang member during the rescue of Colby Granger and Dwayne Carter in "Trust Metric" (S04E01). Also used by a bus hijacker in SO5E12.
Team deals with this hazardous weapon in season 6 episode "Arm in Arms" It seems to have n SL8 stock, what may be a 20-round M16 magazine, and a vague XM8/SCAR resemblance.
A Type 69 launcher is first used by a Charm School Boy member in Season 1's "Uncertainty Principle" (S1E02). The Type 69 launcher also is used by gangsters in order to free a prisoner in Season 4's "Trust Metric" (S4E01).
