When Ann Gorman is speaking with Police Sgt. Art Collins; there is a man sitting on the stool on the right side of Collins. But on the next immediate cut; no one is sitting there.
Because of the abundance and age of the stock footage employed, the age of the automobiles is more often pre-WWII rather than post-WWII, and frequently changes from one scene to the next. Detective Grant drives a 1939 Buick, unusual in itself because it was already ten years old at the time, but a 1942 Chrysler shows up in its place in some of the stock footage. Likewise, the taxicabs continually range from pre-WWII to post-WWII models.
When Police Lt. Harry Grant enters the Tavern from out in the rain; his coat is dry. But on the following cut which is a long shot; the shoulder areas of his coat are now wet. Then after that when he is sitting at the bar with Ann Gorman and Collins; the coat went back and forth between wet and dry.
When McGill is recounting the event that led to him being thrown out of his office window; during the flashback, you can see through the window a heavy downpour of rain. But on the cuts of him lying on the ground and talking to the Detectives; there are no signs of that it has been raining anywhere including the streets and on McGill's clothes.
When Grant after leaving the office is driving in the rain; there is a long shot of the car with the driver's side window fully opened. But on the next shot which is a close-up; the window is now only half-opened.
When Harry and Ann are driving in the rain to the homicide call on Maple Avenue, they take an "S" curve through the city. In that shot, there is a large lighted sign for "Mid-City Garage" that is obviously reversed, indicating, for at least that one short shot, the film had been flipped.
When Grant is in his office and talking to what is supposed to be the "Judge" dummy; the dummy is seated with its back turned to Grant and is wearing its original pin-striped suit. But as Grant continues speaking to the dummy; a partial shot of dummy's front side is shown and now the dummy is wearing a different suit. It turns out that the "dummy" is a real person pretending to be the judge dummy. However real or not, the same object is shown wearing two different suits.
When Grant is driving; at one point there is a long shot of his and other cars driving through the heavy rains. However, the pedestrians on the sidewalk are standing around as if it is a clear evening. They do not have umbrellas and are not running or hiding from the rain. This indicates that either the range of the rain apparatus used was limited to the streets and not used on the sidewalk; or that the rain was inserted during post-production. From the looks of it; it appears to have been inserted during post-production.
When criminals are first brought in to the lineup alongside the dummy; there is a dialog muted shot of Grant giving out instructions. But in the next lineup; the exact same footage of Grant giving out instructions used previously is used again except that it was cropped.
When Grant is driving in the rain after leaving the office; his driver's side window is half-way open. When there is a heavy downpour of rain; people do not drive with the driver's side window open unless there is a practical reason for doing so and the film doesn't provide one.
When Detective Grant is in the office trying to solve the serial killings; he begins talking to the "Judge" dummy that is sitting on a chair with its back turned to him. After Collins interrupts him and they both leave the office; the dummy comes to life. It turns out that the real killer hid the dummy and took its place sitting on the chair. The puzzling thing is that the film does not explain how the killer manages to enter the Police precinct and the Detective's office without being detected. In addition, why would the killer want to go there and how did the killer in the first place even know the existence of a lookalike dummy. Finally, Detective Grant has been practically living with this dummy so it makes no sense that he couldn't tell even from the back that it was a real human being there. All these factors briefly interrupted the flow of the story.
When Charlie Roy is in front of his building; he takes his glasses off and starts running. The whole time leading up to that moment he wore glasses therefore it makes no sense for him to take them off now. In addition, throughout the entire chase, he is able to function easily without glasses so why did he even need to wear them in the first place. These factors tend to interfere with the flow of the film.