Continuity mistake: In the scene where we see that there is shoe polish on Harris' bullhorn, when he approaches Eric Lassard, he's holding his baton by the shaft. In the close-up, he's holding his baton close to its handle.
Continuity mistake: At the start of the film, Mahoney is wearing a white shirt with badges on it from the company he works for. When he's being interrogated by Sgt. Reed the shirt remains the same until the last part of the scene. The camera stays on Mahoney and we can see that the badges on the shirt are gone. If you look closely, you will notice that he is even wearing a completely different white shirt, which now looks more scruffy and creased. (00:08:00)
Continuity mistake: Near the beginning of the movie when Mrs. Fackler runs through numerous backyards, including swimming in one part, to stop her husband from joining the Police Academy, her robe is soaking wet. When she gets on top of the station wagon, only her hair is wet, her robe is mysteriously dry. (00:10:15)
Continuity mistake: When Harris is walking through the cadet's barracks as they're sleeping, he walks into Jones' and Barbara's room and sees Jones pretending to play an arcade game. In a close up shot of Harris, he is seen with a white cloth in his right hand. In the next shot, the cloth is now in his left hand.
Continuity mistake: When Mahoney first meets Jonsey, his (Jones') hands are cuffed behind him. Then he demonstrates why he's there in the station. His left hand has the cuff on. Then it's behind him again. Then, as he goes to mime playing a harmonica after Mahoney is led away, he rubs his right wrist as if it were cuffed the whole time.
Continuity mistake: The patches on Mahoney's shirt switch sides during the movie.