It was Jill because Charlie was seen with Gale and Robbie right before Rebecca was killed. The Ghostface that called Rebecca sounded very sadistic which Jill was..The main clue is that the killer ran at her and onlly stabbed her once which was Jill's MO.
After Nina's back is slashed, did she mutter "Oh, my God." before facing Ghostface? Also, when Nina is crawling away, did she say "Please don't." right before Ghostface picks her up and slits her throat?
Im a massive scream fan, i watched them all in a marathon at a friends house one time and absolutly loved it and now i watch each one at least once a week. i made my own ghostface costume and joined this website. my favourite killer is Stu because of his lethal goofiness.