Medford police have released a sketch of a knife-wielding man who robbed a Lumpy's tavern Friday night.

Medford police have released a sketch of a knife-wielding man who robbed a Lumpy's tavern Friday night.

The man entered the tavern at 801 S. Riverside Ave. at about 7:40 p.m. and demanded money from a female clerk, the Medford Police Department reported.

The man was aggressive toward the female clerk behind the counter. At one point he walked forward and pointed the knife at her, police said.

"His behavior is a concern to us," Medford police Detective Sgt. Mike Budreau said. "Any time a weapon is involved in a robbery, you never know what could happen."

The suspect was described as white, 25 to 30 years old, 5 feet 8 inches to 5 feet 9 inches tall, with a thin build, police said. He was wearing faded blue jeans, a blue zip-up hooded sweatshirt and a cap.

The man ran off and disappeared before police could put a cordon around the neighborhood.

The release of the sketch comes a day after Medford detectives arrested a 20-year-old man for allegedly robbing six Purple Parrots since April. That suspect used a silver handgun and wore a ski mask during those robberies.

Anyone with information regarding the case is asked to contact the police department at 770-4783.