Dragnet (1967)

Joe Friday's carry gun is the Smith & Wesson Model 36 Chief's Special. In episode 21, "The Shooting Board", Sgt Friday shoots and kills a laundromat burglar who fires first on Friday. In one scene Sgt Friday is asked for his gun so SID, Scientific Investigation Division, can do balistics tests on it. We see a profile of the gun in Friday's hand with Friday saying something like, "Hear is my Smith & Wesson revolver,". From that episode and scene, I conclude his carry piece must be a model 36. In the brief shot where we see Friday's gun in profile, it has the distinct thin grip of the Smith & Wesson. This distinguishes it from the Colt Detective Special so many claim Friday carried. To my knowledge his gun is never competely identified in the series.