The employee, Marquise Boyd, 23, and his alleged accomplice, Haili Bernard, 28, are both charged with armed robbery with a handgun.
Around closing time Sunday night, Bernard entered the business in the 2200 block of North Lincoln Avenue through a side door with a handgun and announced a robbery, police said.
The employee ran for the front door, apparently catching Bernard by surprise, according to police. Bernard grabbed the employee's cell phone and fled.
Police said an investigation found that Boyd helped Bernard plan the robbery.
Boyd, of the 300 block of East 50th Street, and Bernard, of the 3500 block of North Milwaukee Avenue, are expected to appear in bond court today.