Third-Generation Glock 17 pistols are carried by B.A.U. (Behavior Analysis Unit) Chief SSA Aaron Hotchner (Thomas Gibson) and Dr. Spencer Reid (Matthew Gray Gubler). At the end of "The Big Game" (S2E14), 'Tobias' (James Van Der Beek) knocks down Reid and briefly threatens him with his Glock 17. Other FBI agents and some police officers are seen with Glock 17 pistols.
Supervisory Special Agent Derek Morgan (Shemar Moore) carries a third-generation Glock 17 with a mounted Streamlight TLR-2 weaponlight/laser module as his duty sidearm.
SSA Elle Greenaway (Lola Glaudini) carries a third-generation Glock 19 as her duty sidearm throughout her episodes in Season 2, the weapon last seen being turned in to Hotch when she resigns at the end of "The Boogeyman" (S2E06). Her replacement, SSA Emily Prentiss (Paget Brewster) also carries a Glock 19. Glock 19s are also seen carried by various police officers.
A Glock 26 pistol is the duty weapon of the B.A.U.'s 'Communications Liaison' SSA Jennifer 'J.J.' Jareau (A.J. Cook). The Glock 26 is also the backup weapon carried by both Aaron Hotchner (Thomas Gibson) and Derek Morgan (Shemar Moore), both carried in ankle holsters.
FBI Senior SSA Jason Gideon (Mandy Patinkin) carries a SIG-Sauer P226 as his duty sidearm. This is a realistic weapon since the FBI did issue the P226.
Various M1911A1 pistols are seen several times throughout the series. One is notably seen used by the unsub known as 'The Fisher King' in the flashbacks of the Season 1 conclusion in the preceding Season 2 opening episode "The Fisher King: Part 2".
A newer model Smith & Wesson 5906 with fixed sights is wielded by a serial arsonist in the episode "Ashes & Dust" (S2E19), but refuses to fire it noticing the benzene-filled building would explode from the muzzle flash.
Reid's captor 'Tobias' (James Van Der Beek) uses a early-version Smith & Wesson Military & Police revolver (Predecessor to the Model 10) to taunt Reid with a Russian-roulette like game several times in the episode "Revelations" (S2E15). Reid also gets ahold of the gun. It can be noted as a M&P revolver due to the Smith & Wesson style cylinder latch (The earliest M&P revolvers lack the typical Smith ejector-rod socket, akin to most older Colt revolvers).
A serial killer known as the 'Hollow Man' is tracked down in St. Louis, where he uses a standard Smith & Wesson Model 29 revolver, loaded with hollow point rounds (hence the name), to kill prostitutes in the episode "The Last Word" (S2E09).
A full-size stainless Smith & Wesson Model 66 Combat Magnum is the sidearm of Sheriff Georgia Davis (Melissa Leo) in the episode "No Way Out" (S2E13). She attempts to use it when she is accosted by an unsub in her home, but is drugged with a heavy dose of Ketamine before she can do so.
A startled homeowner uses what appears to be a Colt Python revolver to quickly shoot a detective and then stand off Morgan in "Fear and Loathing" (S2E16).
Throughout the series, FBI SWAT and several local police tactical units carry M4A1 carbines, both standard models and variants with various accessories.
In "Distress" (S2E17), Roy Woodridge (Holt McCallany), a U.S. Army Ranger and veteran of Somalia suffering from a PTSD-related psychotic break, sees militia with various AKMs, but it's an illusion as they are actually SWAT officers with M4A1 Carbines. In a retelling of his past, he can be seen killing a child soldier armed with a Norinco Type 56.
In "Psychodrama" (S2E04), the bank robber Sheppard (Jason Wiles) uses a MAC-10 fitted with a barrel shroud throughout the episode. In a brief standoff, he convinces a guard to surrender based on the fact he'd go down spraying at civilians.
In the episode "Distress", a flashback shows Somali militiamen riding in a pickup truck converted into a 'technical'. The vehicle has a Browning M2HB heavy machine gun mounted in the bed.
A Remington 700PSS model is seen in use by various SWAT teams. In "Distress", a SWAT sniper uses the rifle to shoot psychologically-fractured Somalia veteran Roy Woodridge, who tried to get a child out of harm's way but this act was mistaken for an attack.
