Shoot them then put a Looter sign on the bodies and just leave them there.
I have this mental picture of one of them positioned on a wall, looking something like a gingerbread man, all sprawled out.
I like your sign. It would be the crowning touch.
"Loot at your own risk suckaaaa!"
I have no problem with people in a situation like this taking food and water and clothing to stay dry. People have children and elderly to take care of. I see no obligation to let those people die in order to keep grocery store shelves stocked with food that will only end up rotting.