I mean it seems weird to me that we'd have 2 SMs in the game, but what do i know. I don't even know if i've ever had a Spirit Medium in a game i've played before, at least i don't remember it. It seems like a "rare" role to me, maybe why i'm surprised about that. If you guys think it's possible we have 2, alright then.
I still don't know about both of them targetting the same dead body. Still think it would be better to have them target different people. It might be a good idea to think about it more before taking a decision.
Anyway, i think the priority target for a SM investigation would be the Prostitute. We might be able to learn that someone was blocked. A det and a spy would not give us anything concrete.