Throughout season 6 Det. Mac Taylor (Gary Sinise), Det. Don Flack (Eddie Cahill) and Det. Danny Messer (Carmine Giovinazzo) carry Glock 17s. Also, any NYPD officer seen with a pistol is using a Glock 17 unless otherwise indicated on this page.
In "Unusual Suspects" (S06E21), Adam Ross (A.J. Buckley) is seen firing a Glock 17 in the gun lab.
In "Battle Scars" (S06E05), a robber is seen with a Browning Hi-Power.
In "Uncertainty Rules" (S06E16), a Browning Hi-Power is seen being used by a thug and later picked up by James Roberts (Joe Reegan) and he holds it on Rufus Knox (Dominic Keating).
In "Cuckoo's Nest" (S6E08) and "Manhattanhenge" (S6E09) , a serial killer named Hollis Eckhart (Skeet Ulrich) uses a Smith & Wesson 3913 "Ladysmith" as his weapon of choice, using it in "Cuckoo's Nest" to kill one of his victims that attempts to escape, and later uses it twice in "Manhattanhenge", using it to pistol whip a store owner and later uses it in a standoff with Det. Taylor and Det. Flack, threatening to shoot himself with it, but drops it at the pleads of Det. Taylor and his own vision of his late wife, Calliope (Josie Davis).
In "Uncertainty Rules" (S06E16), a fake Walther P99 is found at a crime seen. It is later identified by Det. Flack as "a water gun filled with tequila". It it also seen in a flashback during the episode.
In "Blacklist (Featuring Grave Digger)" (S06E02), Junior Mosley (Evan Jones) is seen pulling a gun out of his waistband when he tries to carjack Aaron Dexter.
In "Uncertainty Rules" (S6E16), Rufus Knox uses a Colt Python, firing it at Det. Taylor and James Roberts, but never scores a hit and runs out of ammo.
In "Unusual Suspects" (S6E21), Troy Castro (William R. Spencer) uses a Colt Python to shoot at NYPD Detectives. It is identified as a ".357" by Det. Bonasera and then is seen being test fired by Dr. Sheldon Hawkes (Hill Harper).
In "Pot of Gold" (S6E17), a Smith & Wesson Model 34 is used by Finnegan Hansard (Kieren Hutchison) to kill two journalist. Because the gun hadn't been cleaned, it jams during the murder forcing the killer to use a gold bar to kill the second journalist. Cam Vandemann (Aaron Ashmore) later picks up the weapon to ward of the killer after it was dropped.
In "Cuckoo's Nest" (S06E08), Bob Tanner (Alex Cranmer) uses a Smith & Wesson Model 36 to kill his old business partner.
In "Second Chances" (S06E11), a fake Salvation Army Santa is seen with a Smith & Wesson Model 36 in his waistband.
In "Rest in Peace, Marina Garito" (S06E18), the Smith & Wesson Model 36 is seen again when it is identified as the gun used by Tony Dirisa (Brian Goodman) to kill Marina Garito.
In "Epilogue" (S06E01), Jake is seen holding a Smith & Wesson Model 340PD.
In "Cuckoo's Nest" (S06E08), Flack is seen using the Smith & Wesson Model 340PD as his back up weapon. Terrence Davis (Nelly) picks the gun up just in time to save Flack from being stabbed.
In "Criminal Justice" (S06E12), ESU members are seen with M4A1s when detaining Antonio Reyes.
In "Redemptio" (S06E19), ESU members responding to a prison riot are seen armed with M4A1s.
In "Blacklist (Featuring Grave Digger)" (S06E02), ESU officers are seen carrying Heckler & Koch MP5A2s.
In "Means to an End" (S06E09), ESU officers are seen with Heckler & Koch MP5A2s while searching for Hollis Eckhart (Skeet Ulrich).
In "Epilogue" (S06E01), a gang of extortionists use a Steyr SPP converted to fire full-auto to shoot up several crowded areas, including a bar in which the CSI Team was in, killing only a bartender and wounding Det. Messer. It is even identified as a Steyr SPP by Det. Taylor, commenting on how it wasn't very accurate.
In "Cuckoo's Nest" (S6E08), during a flashback a deranged man is seen using a Mossberg 500 kill his girlfriend, and then uses it to shoot up the other employees at the City Surveyor's Office, including the wife of serial killer Hollis Eckhardt (Skeet Ulrich), Calliope (Josie Davis) wounding Eckhardt in the face with it in the process.
In the CSI crossover episode "Hammer Down" (S06E07), Dr. Ray Langston (Laurence Fishburne) uses a Remington 870, although in a continuity error this changes to a Mossberg 590. Multiple Remington 870s can also be seen sitting in the ESU truck.
In "Vacation Getaway" (S6E23), Detective Flack can be seen with a Remington 870 shotgun.
