Police said a lone man entered the store about 5:30 a.m., shortly after it opened, brandished a pistol and ordered the clerk to give him the money from the register.
She handed him the small amount of cash on hand and he fled.
Using her description and visual information from a surveillance tape, police began searching for the suspect.
Guillory was also charged with simple burglary. No information was provided regarding what incident that charge deals with.