Goofs

When Martin flees from his bungalow into the sewer system, the first shot shows him running with a flashlight and a bag in his hand. This is the same shot as used earlier on in the film after he started robbing liquor stores. (In this later scene, he did not have a bag when he fled the bungalow nor when he entered the sewers.)

A revolver ejects its spent casings only if the shooter does so manually, which Richard Baseheart didn't do, therefore the police could not have even had them to compare with the fired casings from the automatic. An even bigger blunder was the photo comparing the two fired shells, they were clearly marked .380 auto, an entirely different round than the .38 special or .45 auto that the police claimed were fired from the same gun. So now there were three different guns used to create this technical error. In addition, when Jack Webb shows his blow-up photos, all three ejector markings are in the precise same location on the cartridge head, a statistical impossibility. In fact, all three are blow-ups of one photograph.

After examining the bullet casings, Lee tells Capt. Breen that the same gun was used to shoot Officer Rawlins and Detective Jones. But Roy actually used a revolver to kill Rawlins and a .45 automatic to shoot Jones.

When Roy Martin confronts Reeves in Reeves' bedroom, Martin's shadow changes position depending upon whether the shot is from behind Reeves or from a closer position.

At the radio shop, the suspect tried to pick the lock with only the pick; a tension bar is also needed. The tension bar puts pressure on the lock, so that when the pins clear, the lock will turn open.

The Narrator states that police cars come into the station with their sirens wailing. Police cars only use their sirens when heading to an emergency and not when heading to the police station.

Code 3 is radio code for Red Light and Siren. With LAPD, only one unit is authorized to run Code 3 at a time not all units as in the movie.

While that may be procedure, in an instance of an officer being shot, all nearby units would respond code 3 and would not be penalized for doing so.

When running through the sewers, electric cords powering the the flashlights are visible

The lettering on Reeves' glass office door ("Positively No Admittance") is backwards. It should be facing out, not in.

Capt. Breen, in the police car, radios for more police and tear gas and gas masks. The dispatcher is heard to respond before Breen releases his radio button. Until the button is released, the person at the other end would not be able to be heard.

A few times the police refer "pick-locks" when talking about the implements used by criminals to defeat locks. The usual phrase is Lock-Pics. Even in the 21st-century lock-pick sets can still be purchased.

Footage of Los Angeles at the beginning of the film includes Avalon Harbor. Avalon is on Catalina Island, 22 miles from Los Angeles.

When Capt. Breen is interviewing Paul, he gets up from his desk and sits down closer to Paul. A shadow of the boom microphone is visible behind Paul, moving onto and then off the door frame behind him.

Despite wearing both shoulder holsters and belt ones, the police in the film never unbutton their coats to remove their handguns. Since drawing one's weapon is more important than remaining fashionable, it's a certainty that they would unbutton before drawing.