So - can dwarves casually murder one another without getting caught?
I had an elite wrestler in a starting game (woo-hoo, rare guilded dwarf!). Sometime during the second year, stuff was kind of going to heck -- way too big migration waves brought with them all sorts of nasties (mostly way-too-brave kobolds and goblins). My dwarves were scattered around outside picking them off one by one and the elite and one of the migrants had disappeared around the backside of my volcano, off doing their own little thing.
After a while, the elite shows back up and proceeds to facestomp the goblins. And then everyone goes back inside and throws a big party.
After a while, I go looking through my unit lists and checked on the elite, and noticed she had 1 'notable kill': one of my other dwarves. I then checked the death log, and yep, sure enough, that missing dwarf was dead. Combat logs offered NO information (not even a 'she threw a punch' message -- just an empty 'There are no announcements.' page.)
As an aside, the elite was very happy with herself.
EDIT:
Could you provide quick-fix instructions to resolve the transformation chances of guilding dwarves? I assume its something I can just copy and paste, but I don't know the appropriate tag and what file+items to do it to.