I doubt the FBI will be able to shed any light on this even if they are actually involved, which I am somewhat skeptical of. We don't even have a fingerprint library here. This is why most violent crime goes unpunished here. On the other hand, what this does tell you is that even in a society where you're almost guaranteed to get away with murder, absolute chaos hasn't ensued and violent crime continues to occur, primarily, between those involved in violent crime. I hope I'm proved wrong, but unless something very unusual happens, I don't think we'll ever find out what really happened. If we do, it will remain word on the street and nothing more.