To be fair, Mississippi reported systematic looting in Biloxi DURING the hurricane. That had to be planned. The reason stated for no looting after the fact was that nothing was left to be looted.
You will always have some so-called looting, but not the level of lawlessness that we saw in NO. In Miami after Andrew there was a National Guardsman that murdered someone while he was deployed. It had nothing to do with the assignment he just randomly murdered someone while away from his Guard duties.