That is how Saddam ruled. We kill scads of these bozos. But when they surrender, its best to put them on trial and get teh kinks worked out. They don't take 20 years like here. A few months delayed is not too much. OTOH, if the Iraqi gov't decides to line em up and shoot them on the spot, I won't lose any sleep either.
To me, they're way past the time when normal legal means would have solved this issue. Their parliament should take a vote and pass a law allowing for it. That way it's legal. There should be an impartial review board, and they should assure that this doesn't become a tool for unsanctioned revenge killings. I'm talking about martial law.