From the Prince William police press release:
Armed Robbery – On February 12 at 9:02PM, officers responded to the 7-Eleven located at 10420 Portsmouth Rd in Manassas (20109) to investigate a robbery. The employee reported to police that a male wearing a mask entered the store and brandished a handgun toward the employee. The suspect forced the employee to open the cash register to obtain money before fleeing the business on foot. No injuries were reported. A Prince William County police K-9 and helicopter from Fairfax County Police responded to search for the suspect who was not located. The investigation continues.
Suspect Description:
Male of an unknown race or age, 5’07”, 220lbs with a medium build
Last seen wearing a red bandanna covering his face, black jacket with a hoodie, blue jeans, and black and white shoes with white soles
