Investigators found human remains in William Spengler's burned-out house, where he lived with his sister, Cheryl Spengler.
The remains are assumed to be the sister's and a medical examiner will determine the cause of death, police said.
Webster Police Chief Gerald Pickering today revealed an extract from a note written by William Spengler, who allegedly shot dead two firemen in New York:
– William Spengler's typewritten note
I still have to get ready to see how much of the neighborhood I can burn down and do what I like doing best, killing people.
The New York killer of two firemen left a note on his plan to "do what I like doing best, killing people".
The Monroe County Sheriff Department have issued a photo of the gunman in the Webster shooting, William Spengler.
A Facebook page that has been set up to offer prayers and support for the Webster firefighters has received 8,794 Likes at the time of writing.
News 10NBC has reported that the gunman named in the Webster shooting, William Spengler, was arrested in 1980 for killing his grandmother, and served time until 1998.
Webster Police: The suspect, William Spengler, 62. He was arrested in 1980 for killing his grandmother and served time until 1998.
The gunman involved in the Webster shooting has been identified as William Spengler, police say.
"The shooter took his own life with a self inflicted gunshot to the head" said police chief Gerald L. Pickering.
The four firefighters involved in the Webster shooting were named earlier by police chief Chief Gerald L. Pickering.
Flowers have been laid outside the West Webster Fire Station shown in this photo by News 10NBC.
The Webster Police chief said the two killed firefighters, including a volunteer officer who was also a police lieutenant, did not expect to be "shot and killed" in the line of duty.