The mid-day robbery occurred around 1 p.m. on Sept. 12 at the Chase bank branch located at 120 Main Street in Port Jefferson. Cops said an unknown man entered the bank, approached a teller and threatened to "harm someone" if he didn't receive cash.
The teller reportedly complied with the man's demands and passed over an unspecified amount of money from the drawer. The man then fled from the downtown bank.
In a Thursday news release, police released a surveillance photo of the suspect.
He is described as a white male between 5-feet 8-inches and 5-feet 10-inches with a medium build and short dark hair. Investigators said he is between 40 and 45 years old and was last seen wearing blue jeans and a black t-shirt.
Anyone with information about the robbery or the suspect is asked to call Suffolk County Crime Stoppers at 1-800-220-TIPS. All callers will remain anonymous.