Reusing same project??!

One of my friends from another school told me he used the same project twice cause he’s a senior and he doesn’t rlly care. I lowk hope it gets flagged but don’t wanna tattle tale since we not in the same event. Could someone please let me know how they will catch him if he uploaded a bunch of screen shots so it isn’t text detection but on a pdf format. Pls tell me the same ppl grade it every year