My Little Pony: Friendship is Mafia

[Karrrrrrrrrrrresche]

Actually I'd realized what I just posted as I thought this little plot through but now that I think further from the town perspective there's also another option: you and I are both lying and entirely independently attempting to fool the other two parties involved.
Just to state it out: I might be a Serial Killer while you're a mafioso, and both of us just happen to get involved in the same lie, gambling that the other is actually a townie and an investigation will go through the other.

I'd thought the best way to secure my role would be to enact the investigation of Sif and go from there at a point when the Investigator felt comfortable spreading the info around. But with that in mind I guess there's really no way to confirm it short of sacrificing two whole investigations and possibly the investigator himself.