this is separate from my other theory, although I do tend to think that is happening too
did all you detectives notice the magic knife covered in blood that all the characters ignore as if it is not even there? I did. and its got me thinking,
01:: what is everyone looking for? you will recall that faith is looking for something and so are the tweedles, methinks they are looking for the knife not sure why everyone thinks the woodsman has or had it
02:: the murder weapon is "something sharp, or Magic"
03:: everyone ignores a weapon, covered in blood, lying on the floor, as if it has a perception filter. "my lips are sealed" also the perception filter.
04:: both faith and snow white could have gained access to it
theory:: its a weapon that possesses people, and then they chop their own heads off and the body walks away with the knife, maybe it used to belong to bluebeard? and he is trying to get it back? so, you know, he is not entirely blameless while at the same time not being the culprit?
it all fits.
problems:: I dont know why the heads are deposited in front of the building, unless bluebeard lives in there or something. problems:: the body of faith should be at Larwences apartment, especially if one goes there first instead of Toads
questions:: does snow white have her neck covered when she appears in the alley?