For the third time this month, a Cedar Mills 7-11 store was robbed at knife-point Thursday, authorities said.

It happened just before 4:30 a.m. at 12595 N.W. Cornell Road and the suspect appears to be the same man who robbed the store on May 4 and May 14, according to the Washington County Sheriff's Office.

WCSO photo

The jacket believed to belong to the robbery suspect.

"The suspect entered the 7-11, walked behind the counter, and threatened the clerk with a large kitchen knife. The suspect took the cash, then left the building and proceeded south toward N.W. Cornell Road," said Washington Co. Sheriff's Sgt. David Thompson.

The clerk reported that the suspect fled with $20 cash. Deputies surrounded the area and brought in a canine team from the Beaverton Police Department but they did not find the man.

The same store was robbed by a man wearing a mask and carrying a knife on May 4 and then again on May 14. Following the May 14 robbery, deputies found a jacket and a ski mask near the store. Detectives believe the suspect meant to retrieve the jacket before fleeing the area, but for some reason was unable to do so.

More: Masked man robs 7-11 at knife-point, gets away with cigarettes

The jacket is unique and detectives need the public's help identifying the owner, Thompson said.

WCSO photo

The back of the jacket says "Rough Draft Korea."

During this latest robbery, the suspect was wearing a blue and white baseball cap. The cap had a blue bill and blue top, but the front section of the hat was white and had writing on it. He was wearing a red bandana over his mouth and nose, a dark colored jacket, dark gloves, dark pants (possibly camouflage), and black shoes.

Anyone with information about the suspect's identity is asked to call (503) 846-2500.