The US gunman who lured two fire-fighters to their deaths died of a self-inflicted shot to the head and wasn’t hit by return fire from a Police Officer, New York State Police said yesterday.

Investigators had still not made a positive identification of the body found in 62-year-old William Spengler’s burned house. They have said they believe the remains are those of his 67-year-old sister, Cheryl Spengler, who also lived there.

Spengler set his home and a car on fire before dawn on Christmas Eve, took up a sniper’s position and opened fire on the first fire-fighters to arrive, authorities said. He wounded two fire-fighters and a Police Officer.

Autopsies showed that volunteer fire-fighter Michael Chiapperini died of a single gunshot and Tomasz Kaczowka was killed by two, Police said.

Trooper Mark O’Donnell said investigators were not releasing information about how Spengler got the military-style Bushmaster .223-caliber semiautomatic rifle, 12-gauge shotgun and .38-caliber revolver found with his body.

He said they were still tracing the history of the guns.

Spengler spent 17 years in prison for killing his grandmother with a hammer in 1980 and was barred from possessing weapons as a convicted felon. Authorities said they had no encounters with him after he was released from prison.

After Monday’s attack, investigators found a typed letter laying out Spengler’s intention to destroy his neighbourhood and “do what I like doing best, killing people”.

The Spengler siblings had lived in the home with their mother, Arline Spengler, who died in October. In all, seven houses were destroyed by the flames Monday.

Police Chief Gerald Pickering said Police may never know Spengler’s motive.

The wounded fire-fighters, Joseph Hofstetter and Theodore Scardino, were upgraded on Wednesday to satisfactory condition.