Well, unless you catch them in the act, there isn’t much you can do.
I would say....triple up on stickers...only after you put a camera (actually two or three) up. You want to have absolute coverage of all directions. When the person comes (my humble bet is that it’ll be a high school teacher or local professor) to knife the second time...because it’s just too tempting with double and triple the number of stickers, you don’t report it to the cops. You go and knife all four of their tires and use a pair of keys to fix up their hood real good.