Residents in a Stamford neighborhood are on edge Thursday after news that a woman was robbed at gunpoint in her home. Police say the suspects, a man and woman, posing as immigration officers knocked on the woman?s door asking to see her papers. Once the woman let them in her Webb Avenue home, police say one of the suspects held a gun on the victim while the other robbed the home. Police have not made any arrests, but neighbors were able to provide descriptions of the suspects.