looter at a fire scene; thief who steals during a fire
Specifically a person who steals from homes or buildings while a fire is in progress, exploiting the chaos.
A looter stole valuables from the burning house.
opportunistic criminal during a disaster; someone who exploits a crisis to commit crimes
Extended figurative use: a person who takes advantage of any chaotic situation (not only fire) to commit theft or other crimes.
There are people who act like looters, taking advantage of the confusion after an earthquake.