Those took place in Newburgh and East Northport.
In the most recent incident, the man entered the bank, located at 721 Fort Salonga Road, armed with a black automatic handgun, approached a teller at approximately 5:35 p.m. and demanded cash. The teller complied with the demand and the subject fled the scene on foot southbound through the parking lot.
The suspect is described as a heavyset white male between 5-foot-5 and 5-foot-8, clean shaven with gray hair. He was wearing a blue baseball hat with writing on the front, sunglasses, an aqua-blue shirt with a logo over the left breast, blue jeans, white sneakers and was carrying a black and blue backpack.
Detectives are asking anyone with information on this incident to contact Crime Stoppers at 1-800-220-TIPS. All calls will remain confidential.