No evidence of any plot, genocidal or otherwise.

Even Marx and Lenin recognized the existence of a "lumpenproletariat," people so degraded that they were useful only as violent enforcers of revolution. These are the sort of people who are being classed as looters along with those who are simply taking food and water. The difference is that the criminals want plunder.

The gangbangers had every reason to stay in town. First, only cowards run from something like a storm. Second, they face death from a drive-by shooting every day, so how's Katrina any different? Third, if they leave, the other gang may come by and torch their house. Some of them don't want to leave a sick parent. And who wants to sit in a traffic jam for hours anyway? Finally, if they stay, they can loot. Maybe they can settle some scores. They can be hurricane kings. (Nobody counted on a flood and the possibility of drowning or starving.)

So no one should be surprised at sociopathic behavior. I don't think city officials are surprised. Anarchy often follows disasters like this.