Have Katrina looters been shot and killed under martial law?

Throughout the reports that I have watched on CNN, there has been much made about looters and the atmosphere of lawlessness and anarchy in New Orleans. When it was reported that several New Orleans Police officers had been wounded by gunfire, the Mayor of New Orleans ordered the police and, later, National Guardmen to secure the peace in the storm stricken city. How was this accomplished?

Under Martial Law, order is to be maintained by any and all means possible including "shooting to kill". As of yet, I have not heard any reports on how the New Orleans Police Force and National Guardsmen were able to regain and maintain security. Were the looters and anarchists of Katrina shot to death?