Kirby and a new character (that is in law enforcement) are the killers (only shot of them getting that much murder evidence is that it came from someone that has the ins on obtaining it). As for Kirby’s motive I can think of a few (remember she was also horror movie obsessed to a certain degree) but in reality I don’t see any reason for her to have a part in this film (as cool as she is) if she isn’t one of the killers.There is a 3rd killer that isn’t caught, and is completely unrelated to them (Stu). In the 7th installment (which will bring Sidney back) Stu’s motive is that everyone looks at Billy as the OG GF and he doesn’t get the credit he believes he deserves and is mostly forgotten about. Stu’s rich ass parents kept him in hiding after paying off the very small/local Woodsboro police department (or someone that is able to fake a claim of Stu’s death). He is there to finish what he and Billy started.

What do you think?