Police say one man is responsible for at least four robberies since February.
The most recent was Tuesday at the Alaska Food Market.
A masked gunman charged in and demanded cash.
Everyone hit the floor, until one got the money from a box and the cash register and the gunman left.
At the Chelsea Grocery, the robber had been in the store a few days before without his mask.
"The guy came in a couple of days before this incident and he tried to rob something, tried to steal a candy bar or a piece of cake, said Sam Mozeb of Chelsea Grocery.
"And my cousin grabbed it from him and said get out of here."
The next time, he was armed.
"He comes in a couple of nights later with a ski mask and says 'Give me all your money,' said Mozeb.
The gunman is described as a male 20-30 years old, 5'6" tall, 160-170 pounds.
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