Police responded to the scene at the gas station in the 10000 block of Fields Road around 2:25 a.m. on Monday, July 26.
The surveillance video shows one suspect climbing over the counter to threaten a clerk, while another suspect comes into the cashier’s area from the side.
Police say the second suspect was armed with what they described as an "assault-style rifle."
The suspects forced the employee to open both registers, and the one armed with the gun struck the employee.
The pair stole cash and ran off toward Shelburne Terrace.
If you have any information that might help police, call (240) 773-5070.