Lt. Carter Shaw (Dylan McDermott) switches his SIG-Sauer P228 to a customized Colt MK IV Series 80 halfway into the first series. The same pistol is also used by Jimmy (Cole Hauser) in the series Chase and also by Detective Ludlow (Keanu Reeves) in the film Street Kings. Before the particular gun becomes Shaw's sidearm in the series, an unknown thug working for Howard (Al Sapienza) can briefly be seen with it, before being gunned down by Curtis in episode "Purity" (S01E03).
Ty Curtis (Omari Hardwick) keeps a nickel plated Colt Government Model pistol in a safe box, alongside a Beretta 92FS. He takes it out and uses it in the pilot episode after Lt. Shaw (Dylan McDermott) sends him back undercover.
Aother M1911A1 is used by Lt. Jay Frye (Michael Biehn) as his sidearm in the episode "O.I.S" (S01E07). His 1911 is fitted with Novak sights.
Jack Walsh (Clayne Crawford) also keeps a 1911 variant as his sidearm in episode "K-Town" (S01E04). He is only briefly seen firing it at Curtis, but he is quickly disarmed by Dean Bendis. His 1911 also seems to be fitted with either Novak or Bomar sights.
Ty Curtis has a Beretta 92FS in a safe box alongside his Colt Government Model in the pilot episode. The Beretta 92FS is also used by a guard and one of Warren Volk's men in the bank during the pilot episode. Dean Bendis (Logan Marshall-Green) also has a Beretta 92FS in a locked box along with his drugs and cash hidden under his floor boards. A Korean gangster, Kang (Brian Tee) also uses a Beretta 92FS in episode "K-Town" (S01E04). A Korean thug is also seen firing a 92FS in the same episode. A couple of thugs working for Dante Rollings (Gbenga Akinnagbe) are also seen with Berettas in episode "August" (S01E05). Officer Noyce (John T. Woods) and Officer Kim (Yun Choi) of Lt. Frye's (Michael Biehn) rogue task force also carry the Beretta 92FS as their sidearms in episode "O.I.S" (S01E07). A Beretta is also seen lying on a table in a drub lab in the same aforementioned episode.
A member of the Korean mafia uses a Beretta 92FS Inox as his sidearm in the episode "K-Town" (S01E04). He is seen assembling it in the beginning, in a race against Dean Bendis (Logan Marshall-Green). He uses it later to try to shoot Dean.
Robert Franzine (James Russo) carries as his sidearm in the pilot episode a Ruger KP90. He uses it most notably in the bank "robbery" during the pilot episode.
Jaimie Allen (Nicki Aycox) carries a two-tone Glock 17 as her sidearm only in the pilot, and can be seen using it in the gun range, and also during the climax shootout of the pilot. Her Glock switches into a Kahr 9 after the pilot, and remains her sidearm for the rest of the series.
In the pilot episode, some of Warren Volk's and Robert Franzine's men carry regular Glock 17s. In episode "Ice" (S01E06) Tommy Franco (Jonathan LaPaglia) keeps a Glock 17 in his safe. Also one of Dan Kemp's (Michael Bowen) heist crew keeps a Glock 17 as his sidearm in the same episode.
In episode "O.I.S" (S01E07) Ty Curtis exceptionally has a Glock 21 as his sidearm, as he is trying to infiltrate a task force, led by Lt. Jay Frye (Michael Biehn). This involves him going back to work as a plain clothes officer. Apparently the Glock 21 was Curtis' duty weapon.
Jaimie Allen (Nicki Aycox) briefly wields a Heckler & Koch USP Compact during a drug deal, that's actually a set up. A thug working for Howard (Al Sapienza) pulls a H&K USP Compact when Howard orders him to kill Reuben Pike in episode "Purity" (S01E03). He is gunned down before he gets a chance, though.
In episode 2 ("Guns, Strippers and Wives"), Jimmy Boyd (Gregg Henry) is briefly seen putting a Smith & Wesson 4506 to the head of Ty. The particular 4506 used in this episode is the exact same one used by Keanu Reeves in the 2008 film Street Kings (same armorer, same prop). A pair of snake eyes dice with "Vice Special" is printed on the right side of the slide between the ejection port and the muzzle. The same prop is also re-used in episode "August" (S01E05), as Dante Rollings' (Gbenga Akennagbe) sidearm. Shaw eventually takes the gun away from Dante, and points it at him.
A Korean gangster puts a Smith & Wesson 5904 on Ty's throat in episode "K-Town" (S01E04), when Dean Bendis is accused of cheating by one of the Koreans.
A drug buyer tries to pull a Smith & Wesson Model 640 Centennial on Shaw in the second episode, when they are trying to come up with a 100 grand to save Ty.
A Smith & Wesson Model 36 snub-nose revolver can be seen Reuben Pike's trunk in the third episode, Purity. Bendis and Allen plant this gun, and some coke, in Pike's trunk to make sure he will be co-operative.
In episode "Ice" (S01E06), Dan Kemp (Michael Bowen) gives one his heist crew a nickel plated Colt Detective Special, saying that if he wants out, he has to play Russian roulette.
In the pilot episode, one of Warren Volk's bodyguards has an unknown snub-nosed revolver in an ankle holster. He tries to use it but is gunned down by one of Franzine's crew members. Lt. Frye (Michael Biehn) is also briefly seen planting a snub nose revolver into the hands of a dead drug dealer in episode "O.I.S." (S01E07).
In the second episode when Ty is undercover he is trying to buy guns from Johnny Moosa. Among other weapons there are Heckler & Koch MP5A2s. Moosa also tests one of the MP5's, which is fitted with a holographic sight. A thug from Moosa's crew also tries to use an MP5A2 during the trade in episode 2, but Dean intervenes.
Most of Robert Franzine's (James Russo) men use M4A1 carbines in the pilot episode, including undercover Officer Dean Bendis (Logan Marshall-Green). They most notably use them during the bank job, and the ensuing shootout. A couple of M4A1s are also seen in episode 2, "Guns, Strippers, Wives": First in the container when Ty Curtis (Omari Hardwick) checks Johnny Moosa's merchandise, and later in the back of a van during the trade off.
One of the weapons that Carter used to stage a fake weapon transportation deal in the second to last episode.
Shotguns
Remington 870
Lieutenant Carter Shaw (Dylan McDermott) uses a Remington 870 shotgun with synthetic furniture, rear pistol grip and extended barrel in the pilot episode shootout near the end.
One of Robert Franzine's (James Russo) men is seen loading a Remington 870 when they prepare for the bank job in the pilot episode. Dean Bendis is also seen with one in episode "Ice" (S01E06) as he robs some robbers of their stuff. Officer Kim (Yun Choi) is also briefly seen with one, when Lt. Frye's rogue task force is outside Dean Bendis' apartment in episode "O.I.S." (S01E07).
Lt. Carter Shaw and Dean Bendis also use tactical Remington 870s fitted dedicated Surefire forend weaponlights whenever they need to make a bust. Officer Allen (Nicki Aycox) is also briefly seen loading one of these Remingtons in episode "K-Town" (S01E04).
A Benelli M1 Series Super 90 is carried and used by one of Lt. Shaw's acquaintance's Neal's (David Fabrizio) men in the episode "O.I.S." (S01E07) during the raid on the drug lab. It is seen fitted with a Surefire tactical light.
In episode "O.I.S." (S01E07) Lt. Shaw's (Dylan McDermott) acquintance, Neal (David Fabrizio) uses an Ithaca 37 shotgun when they destroy a drug dealer's lab together.
