Alien Nation - The Series was a science fiction television series based on the 1988 film of the same name that starred James Caan and Mandy Patinkin. The series ran for 22 episodes on the FOX network and was later resurrected in several made for TV films. In the series, Gary Graham starred as Detective Sikes and Eric Pierpoint as Francisco.
The following guns were used in the series Alien Nation - The Series:
An overseer shoots a Smith & Wesson Model 60 revolver in "Contact" (S01E08). Sikes former partner Theo Miles (Gilbert Lewis) in "Partners" (S01E16) has a revolver as well. Brian Knox / Dr. Death (Tobin Bell) uses this revolver in episode "Crossing the Line" (S01E18).
One of the gang members drops what appears to be a Smith & Wesson Model 10 revolver in "Pilot" (S1E01). Buck Francisco (Sean Six) gets hold of it during the fistfight with the gang.
Smith & Wesson Model 66 Revolver
Kenny Dunstan (Charley Lang) has a Smith & Wesson Model 66 when he enters the police station in "The Takeover" (S1E05). Sikes has a Smith & Wesson Model 66 in an flashback in the episode "Crossing The Line" (S01E18) where he is still a young police officer.
In the film Alien Nation, Sikes carried a Model 92FS, but in the television show, the character carries a Beretta 92SB pistol.
Smith & Wesson 659
Some footage from the in footage that was used in the pilot episode and was taken from the 1988 film was used in the pilot episode to tie the story together.
Smith & Wesson 669
The Smith & Wesson 669 was the issued sidearm carried by Detective Francisco.
M1911A1
One of the gang members fires what appears to be an M1911A1 pistol in "Pilot" (S1E01).
A police officer uses a Mossberg 500 Cruiser shotgun with a pistol grip and a forend weaponlight during a raid in "Partners" (S01E16).
Benelli M1 Super 90 Shotgun
A modified Benelli M1 Super 90 Shotgun is used by Rudyard Kipling (Kevyn Major Howard) in footage that was used in the pilot episode and was taken from the 1988 film. The shotgun is fitted with a pistol grip stock, extended magazine tube, rifle sights and modified for the movie to use box or drum magazines, used by the "Slag" robbers at the beginning of the movie.
Franchi SPAS-15
Francisco gets ahold of a Franchi SPAS-15 shotgun in "The Takeover" (S1E05). It is seen in the hands of policemen in later episodes.
Remington 870 Shotgun
One gangster fires his Remington 870 at Sgt. Francisco in "Fountain Of Youth" (S1E02).
The Hitman in the episode "Fifteen With Wanda" (S1E04) throws a M67 hand grenade into the room.
Water Pistol
In "Pilot" (S1E01), one of the gang members has a yellow water pistol to spray salt water on one of the Newcomers because it reacts like acid. The model might be the same model as the one used in the movie Cop and a Half.