"Peeping Tom" 1960 considered one of the original slashers, pretty tame today, but an interesting, understated watch, though I found it a chore to get through at points. So many earlier movies lacked pacing, or seem to struggle to find the kind of motion that more modern film does. Also, you are watching these kinds of movies, the classics, and it seems like you have seen it all before, because, of course, you have, it's many imitators, but still can feel sort of predictable.