After watching tonight's episode of Fox's Scream Queens, my theory of who the final killer is seems more likely. If you haven't watched the episode yet, I apologize for ruining it for you. Tonight we saw the Red Devil kill Boone after he almost jeopardized Gigi's plans for revenge on the Kappas. Boone reveals himself to Chanel #3, who thinks he's a ghost. She then tells the other Chanels that he's come back to get revenge on her.
Anyway, for the entire season, I've been suspecting Chanel #3 to be the third killer because of one major clue. Most people know Ryan Murphy enjoyed inserting clues about each season of American Horror Story in the season before it. So who's to say that he wouldn't have done that for this show?
One thing I've noticed throughout the season is that a few characters had a pair of ears as part of their wardrobe.
Chanel #5 has worn these ears in a few episodes. Along with another pair made of different material.
And another character who has worn ears was Zayday Williams, towards the beginning of the season.
So the reason I think this clue is so important is because we see Chanel #3 wearing earmuffs pretty much the entire season. In one episode, she says that she wears them because she used to be an ear model and one guy was so in love with her ears that he went insane.
Could it be that the ears are a clue pointing to Chanel #3 as the third killer? Her father was Charles Manson so she could have the killer genes in her.