Brookline police are looking for a man who robbed a bank near Coolidge Corner on Saturday morning. The suspect, whom police described as a 6-foot white male in his mid-20s with a tattoo on the right side of his neck, entered Eastern Bank, at 301 Harvard St., around 11:20 a.m. He was wearing a long-sleeved striped shirt, white baseball cap with the New England Patriots logo, and sunglasses, police said. He showed the teller a note indicating that he had a gun and demanding money, police said, and fled on foot. Police Lieutenant Philip Harrington said he did not know whether the man took any money. Anyone with information can call Brookline police at 617-730-2222.