Movie about time Freezing/Stopping at night.?

I cant remember the name of a movie i saw, and need help. I was probably made in mid 90's/ All i can really recall is that every night time would freeze or stop and these little bald, white people in all black would walk around the city and erase peoples minds, or change the way they thought. It seemed like the city was more of a Gotham City type of feel to it. I also remember the main character being a detective and for some reason it didnt work on him.