The victim had gone to work early to open the business for the day. She was discovered unresponsive when another employee arrived at the location, 1302 E. Patrick St.
Coworkers performed CPR on the woman until police and EMS arrived shortly after 6 a.m.
The victim was pronounced dead on the scene. She died of an apparent gunshot wound, and police are investigating the case as a possible robbery/homicide.
Police have not released the victim's identity, pending notification of relatives.
They are calling this case rare, citing the fact that Frederick had only two murders in 2010.