It happened at the Haverford Avenue Dollar General on Nov. 7, authorities said.
A masked gunman strode into the store just after 8 p.m. and forced employees to empty the safe and register into a plastic bag, according to police.
Investigators say the robber made off with several hundred dollars and fled on foot. He was wearing a "security uniform" and a green and yellow mesh hat, they added.
Anyone with information is asked to call PPD at 215-686-8477 or submit a tip anonymously online.
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