Police are searching for a man who robbed the 7-Eleven at 18075 Fraley Boulevard in Dumfries on Monday night.
The robber entered the store at 10:31 p.m., approached the clerk, brandished a weapon and demanded money.
The suspect took an undisclosed amount of money before fleeing on foot. No injuries were reported. A police K-9 search for the suspect who was not located.
The suspect was black, between 23 and 27 years old, about 5 foot 5 and 170 pounds with a medium build and light complexion.
He was last seen wearing a mask, gray hooded sweatshirt, and black pants.
Anyone with information is asked to call Prince William County police at 703-792-6500.