Nobody was murdered [Speculation]
Or at least they weren't killed directly. It's the ribbons. Only prostitutes have died and all of the girls are wearing those ribbons. The victim's head was always cut off and the ribbons are always connected to their neck. When we attempted to take Merissa's off she was clearly distraught and afraid for her life. So maybe when they attempt to talk or when something gets triggered the ribbon activates and offs them.
The only flaw in this theory is that if it's just when they talk or somebody attempts to take off the ribbon then there should be more witnesses and the deaths should include less planning. We've only heard of the bodies being placed somewhere , we haven't actually learned anything about the deaths. So after Faith and Lily died both their heads were placed in front of the building to send a message.
Comments
Unless someone invited/lured them somewhere private and then took the ribbon off. I agree with the ribbon theory, what I can't figure out though is why the Crooked Man would want them killed. His ribbon thing is foolproof as far as keeping them shut up. They literally cannot talk without killing themselves in the process. So, I don't know why he'd be threatened enough to kill them. Also, they make him money. They're much more valuable alive than dead. Smart pimps with good business sense don't want to kill a hooker who could be worth literally hundreds of thousands of dollars (I got this estimation of "The Wire" when a bunch of hookers were killed in the 2nd season). I think that they must've talked (but then, why were the heads placed on the steps) or they were killed by someone other than the Crooked Man or they were killed by the Crooked Man for reasons we haven't even fathomed yet.
Crooked Man didn't want them killed. They committed suicide to expose the Crooked Man's black market to the last honest people in Fabletown: Snow and Bigby.