Help getting my murderhobo party to roleplay.

[The Oni]

Sarcasm doesn't always translate well through the 'Net.

The whole bounty-hunter/vigilante concept isn't inherently bad, although again, if they're terrorizing poor townsfolk they may not be able to realistically hire anyone who's a threat to you.

I actually wrote a group in a 3rd party setting that's a cabal of witches and spiritualists that take on missions of revenge, for whatever the target can pay and sometimes for free if the story is moving enough - designed explicitly to give players a hard time for being douchebags to commoners. They generally antagonize the target with curses, hauntings, thefts and general paranoia, though killing isn't entirely out of the question if they feel the target is awful enough, and their one rule is never to harm a child in the course of the revenge.

But again, yes, the most important bit is that the players need to be involved in the discussion. If you just start punishing them without encouraging them to roleplay in positive ways, they're not gonna go for it. In fact, they may just get more murderhobo-y in defiance.