I think either Sezam and Snowman, or Doug and Alex are the mafia. By the way, I had a guess about Sezam, and yesterday, based on her posts, I would have thought she was mafia.
Execute Sezam, for now.
If anything, I can switch to any of the above.
Added 2 minutes later
More precisely, in the second option, Alex is mafia, and Doug is a town member.