First by process of elimination it comes down to Light, Mel and Yo
Yo seems kinda out of character this game (sorry Yo, I'm not trying to offend you)
Also I said earlier that he has been very vague about his abilities, like visiting Fuji D1 but no effect on Fuji, no info to claim, no nothing. So it's a little odd, what I'm guessing is he is mafia invest.
He townread Queen earlier (but I mean a bunch of us did too). Jew's results failing on him is also sus. I played a game before where everytime invest investigates one of my mafia buddies, they'll get a failed results