on the killing of wounded soldiers...

There's been much written in the blogosphere about the U.S. Marine who shot and killed that already-wounded Iraqi insurgent in a Falluja mosque recently. Kevin Sites, the embedded journalist who broke the story says (on his own website):

"To Devil Dogs of the 3.1:
Since the shooting in the Mosque, I've been haunted that I have not been able to tell you directly what I saw or explain the process by which the world came to see it as well." FULL STORY >>>

And there it is. From the horse's mouth (what I'd call a primary source).