A man was shot and killed by a police officer Saturday afternoon during a struggle over a gun. Units responded to a disturbance call in the 900 block of Andean Goose Way in Upper Marlboro at approximately 3:30 p.m. yesterday. The mother of the man told officers that her son was acting erratically and had a shotgun inside the house. Her son had a history of mental illness. Officers determined that the man should be evaluated at a hospital because he was a danger to himself and others. However the man resisted going to the hospital and assaulted an officer. While struggling for the officer’s gun, another officer shot the man fatally.