I recommend that you don't join Biotracks' Super Murder Mystery if you like killing tons of people as mafia: I was mafia, and had a great opportunity to kill many people at once (all of which were innocent), so I took it and knocked out plenty of people and ended up with this:
Instant perma'd
Proof I was mafia at the time:
So even if you're mafia, you'll get banned for "RDM" even though the point is to kill the innocents as mafia, which is exactly what I did (albeit no where near stealthly).