Robert Waters was charged with second-degree murder after police found Florence Trosani, 90, beaten Tuesday night at 43 W. Court Dr., police said.
Trosani was pronounced dead a Stony Brook University Medical Center, police said.
A police spokeswoman said Waters, his fiancee -- who was not identified -- and Trosani lived together at the home.
Officers from the Sixth Precinct went to the home at about 9:20 p.m., responding to a 911 call for a man needing medical attention. Upon arriving, police said they checked on Waters, who needed medical attention, but an investigation revealed that another person was in the home. Officers found Trosani, who was taken to the hospital.
Waters also was transported there and admitted for observation, police said. Police did not provide any other information on his injuries. He will be arraigned at a later date, police said.