The Frederick County Sheriff's Office is looking for a man who robbed the Middletown Exxon at 122 Reliance Road on Monday evening.
The suspect, who has not been identified, entered the store at about 5:30 p.m. and walked around in it for a few minutes, according to a news release.
The man approached the clerk with what the clerk described as a folding utility knife, pointed the knife at the clerk and then demanded money, authorities said.
The store clerk then gave the suspect an undisclosed amount of money, and the suspect fled on foot, Sheriff's Office officials said.
No one was injured. The suspect is described as in his early to mid-20s, and about 6 feet to 6 feet 2 inches tall. Anyone with information is asked to the call the Sheriff's Office at 662-6162 or Crime Solvers at 665-TIPS.