When Principal Robbins opens the locker for Detective Van Zandt, the locker has a keyed combination dial on it. When Van Zandt slams the locker shut, the dial is missing and there are holes in the door where it was moments before.
When Alicia is being interrogated she asks for a cigarette and Detective Mcready pulls out a pack of Marlboro reds, which are "full flavor" and have brown filters, and hands her one. A minute later when Alicia snuffs the cigarette out in an ashtray is has a white filter, like "light" cigarette has.