Police have found human remains in the burned-out home of the New York state ex-convict who killed two firefighters and believe the victim is the gunman's sister.
Police Chief Gerald Pickering said on Tuesday the remains were found in the charred house that 62-year-old William Spengler shared with his 67-year-old sister, Cheryl. A medical examiner will need to determine the identity.
Police say Spengler armed himself with a revolver, shotgun and military-style rifle before he set his house on fire to lure first responders into a pre-dawn death trap on Christmas Eve.
Pickering says Spengler "was equipped to go to war".
Spengler killed himself as seven houses burned around him. A friend said Spengler hated his sister, but police say a motive has not been determined.
It was revealed by police earlier on Tuesday that Spengler also left a typewritten note saying he wanted to burn down his neighbourhood and "do what I like doing best, killing people".
The two to three-page note left by Spengler did not give a motive for the shootings, Pickering said.
He declined to divulge the note's full content or say where it was found, but he read one line from it: "I still have to get ready to see how much of the neighbourhood I can burn down and do what I like doing best, killing people."
Spengler served 17 years in prison for the 1980 hammer killing of his grandmother.
The dead men were identified as police Lieutenant Michael Chiapperini, 43, the Webster Police Department's public information officer; and 19-year-old Tomasz Kaczowka, also an emergency dispatcher.
Pickering described Chiapperini as a "lifetime firefighter" with nearly 20 years in the department, and he called Kaczowka a "tremendous young man".
The two wounded firefighters, Joseph Hofstetter and Theodore Scardino, were in stable condition on Tuesday, the chief said. Both were awake and alert and are expected to recover.
Authorities said Spengler had not done anything to bring himself to their attention since his parole.
As a convicted felon, he was not allowed to possess weapons. Monroe County District Attorney Sandra Doorley said Spengler led a very quiet life after he got out of prison.
A friend said Spengler hated his sister. Roger Vercruysse lived next door and recalled a man who doted on his mother.
"He loved his mama to death," said Vercruysse, who last saw his friend about six months ago.
Vercruysse also said Spengler "couldn't stand his sister" and "stayed on one side of the house and she stayed on the other".