Police are questioning the stepfather of a man who was shot and killed yesterday in his Canarsie home, naming him as a possible suspect in the case. Police say Osvaldo Vasquez, 43, was shot in the chest at around 6 p.m. at the Breukelen Houses on Glenwood Road. He was rushed to Brookdale Hospital, where he was pronounced dead on arrival. Investigators have taken his stepfather, Dolores Fuentes, into custody after recovering a gun at the scene. According to a family friend, Fuentes stated that the shooting was a mistake. The victim's mother says Fuentes was holding the gun when it accidentally went off.