WEST BABYLON - Suffolk police are searching for a suspect who they say may be responsible for a series of bank robberies, the latest of which took place yesterday. Authorities say a "husky" man in his 50s walked into the Roslyn Savings Bank on Montauk Highway in West Babylon at around 1:30 p.m., went up to a teller and demanded cash.The robber got away with an unknown amount of cash. Police are investigating whether the same suspect is responsible for other robberies in Suffolk County.