That was fast.
NOTE: I'm gonna "retcon" this event a little bit. When Joa told Dylan of this in Book 1 chapter 2 he said he killed these dudes because he needed to
feed, but now that I think about it he has Marcel's blood in him right
now so he really doesn't need feeding, so he just beat the shit out of
these dudes, but didn't drink their blood. I edited the dialogue on that page a little bit. :)