Looter
/ˈluːtər/
Definition 1 of 1
Pro Tip 1/3Negative Connotation
The word 'looter' is pejorative, implying a wrong or immoral action during chaotic events. 
The city was under curfew after reports of looters in the downtown area.
Pro Tip 2/3Specific Contexts
'Looter' is used specifically when the stealing is in the context of larger-scale unrest or emergency situations. 
In the aftermath of the hurricane, looters were seen taking advantage of the abandoned shops.
Pro Tip 3/3Implies Opportunism
'Looter' often implies someone opportunistically stealing during confusion, rather than premeditated theft. 
As the blackout continued, some looters began to target electronics stores.