Authorities in Watertown are investigating a bank robbery that occurred late Thursday afternoon. Officials say a man in his late 20’s to early 30’s entered the Associated Bank on Main Street around 5 p.m. The man demanded money by passing a note to the teller though it’s unknown if he was armed. Police are not releasing how much money was stolen. The suspect is described as a white male, 5’10” to 6′ tall, medium build, with a full beard and mustache wearing a dark baseball hat, black pullover shirt, and blue jeans. Anyone with information is asked to contact the Watertown Police Department or the anonymous WE-Tip Line at 1-800-78-CRIME. Police are also offering a reward $1000 for information resulting in a conviction.