Near the end of the movie after the mother has shot the villain, there's a closeup of police surrounding the mother.

Notice a semi-automatic pistol on the right side of the screen. Notice that the cop has his thumb on the back of the slide. If he were to actually fire the pistol, his thumb would be quickly dislocated if not completely removed by the recoil action of the pistol. Surely there was a firearm consultant on the set, he missed this one big time.