These cases aren't going to stand on forensic evidence. It'll be based on the testimony of the participants (which is how it came to light in the first place).
Ten bucks most of these guys have already cut deals with the prosecutors.
The question is whether they would be subject to an Iraqi trial. I currently have a call into a friend who is both a JAG officer and a deputy prosecutor to get an answer.
You may be right but we'll have to wait and see what happens at the ART 32 hearing.