A chilling typewritten note from the gunman who ambushed firefighters in New York state on Christmas Eve said he intended to burn down his neighbourhood and “do what I like doing best: killing people.”

Webster police Chief Gerald Pickering released more information Tuesday morning about the incident that left two firefighters dead and another two firefighters in hospital with serious injuries. Police say a gunman set fire to his home and a car and then waited for first responders to arrive, when he opened fire.

On Tuesday, an emotional Pickering said police and fire investigators converged on the scene on Lake Rd. “at first light” Tuesday to sift through the debris for evidence, and potentially more victims.

Authorities located human remains presumed to be those of Spengler’s 67-year-old missing sister, Cheryl Spengler. A medical examiner still needs to identify the body and determine cause of death.

The siblings lived together with their mother Arline, before she died in October.

Seven homes burned down before firefighters got control of the blaze. They were still battling hotspots on Tuesday morning.

Pickering said investigators found a three-paged, typewritten note left behind by the shooter. While he would not release its entire contents to the media, Pickering did read one line to reporters that he said made the shooter’s intention clear.

Pickering quoted the note as saying, ‘“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.”’

Police have said the suspect set fire to his home and a car and then opened fire on four firefighters as they arrived on the scene shortly after 5:30 a.m. Monday. He exchanged fire with a police officer before killing himself.

Two firefighters died and two others remain in hospital with serious injuries, Pickering said.

Police have identified the suspect as 62-year-old William Spengler, who was convicted of manslaughter in the 1980 death of his 92-year-old grandmother. Spengler spent 17 years in the New York State prison system before being released on supervised parole.

Pickering said Tuesday that Spengler had “armed himself heavily,” and had taken up cover in a natural depression, where he waited for first responders. Pickering said police have found a shotgun, a rifle and a handgun. Spengler’s body was found on a berm near his home.

“This was a clear ambush,” Pickering said Tuesday, reiterating comments he made hours after the incident.

Spengler lived with his 67-year-old sister, Cheryl Spengler, who remained unaccounted for Tuesday morning, authorities said.

Their mother, Arline, also lived at the home before she died in October.

As a convicted felon, Spengler could not legally own firearms.

Monroe County District Attorney Sandra Doorley said Spengler lived a quiet life after his release from prison, and had not done anything to attract the attention of local law enforcement.

Roger Vercruysse, who lived next door to Spengler, said he was a devoted son.

“He loved his mama to death,” Vercruysse said, adding that Spengler “couldn’t stand his sister.” The siblings kept their distance when at home together, he said.

The two deceased firefighters have been identified as Lt. Mike Chiapperini, who was both a firefighter and a member of the Webster police, and Tomasz Kaczowka, a volunteer firefighter.

Chiapperini, 43, was named Firefighter of the Year just two weeks ago, and had recently taken vacation time to help recovery efforts after Hurricane Sandy, according to a local newspaper. He is survived by his wife and three children.

Kaczowka was just 19 years old and worked as a 911 dispatcher for Monroe County. He was also a student at Monroe County Community College.

The injured have been identified by police as firefighters Theodore Scardino and Joseph Hofstetter.

Dr. Nicole Stassen, a trauma physician at the University of Rochester Medical Center in Rochester, N.Y., confirmed Monday that Scardino and Hofstetter are being treated at the hospital for "significant injuries."

She said Scardino suffered two gunshot wounds, one to his left shoulder and the other to his right knee.

Stassen said Hofstetter has a "complex" injury resulting from a bullet that struck his pelvis. The bullet is embedded in part of his spine and has not been removed -- and likely never will be, she said.

Both men are in intensive care and were in stable condition Tuesday morning.

The officer who exchanged gunfire with Spengler, John Ritter of nearby Greece, N.Y., was treated and released from hospital, Pickering said Tuesday, noting that the policeman tried to shelter the wounded firefighters with his car.

Investigation continues

Meanwhile, an investigation is ongoing at the scene on Lake Road, which is located on a narrow peninsula where Irondequoit Bay meets Lake Ontario, just east of Rochester.

On Monday, houses in the immediate area were evacuated using an armed personnel carrier.

After smouldering for several hours, fire crews managed to contain the Lake Road blaze. By then, Pickering said seven homes had been “totally destroyed.”

Police said they have yet to determine if there are any other victims in those homes.

On Tuesday, Pickering said the size of the crime scene has been reduced and some residents have been allowed back into their homes.

Pickering grew tearful when he thanked local residents for their support Tuesday. He said the West Webster Fire Dept. has been inundated with calls and offers of donations from both police agencies and civilians around the world.

“I want to thank the community for a tremendous outpouring. It has been incredible,” he said.

About 100 local residents held a candlelight vigil Christmas Eve outside West Webster Fire Station 1, where nearly two dozen bouquets rested on a bench alongside handwritten signs of thanks. While firefighters declined to speak, a department spokesperson thanked the mourners before asking them to return home and be with their families.

Cathy Bartlett, who attended the vigil with her teenage son, said she was thankful that her husband, Mark, a firefighter, missed the call.

“Thank God my husband slept through the first alarm and didn’t get up until the second one went off,” she said.

Pickering also asked for residents and media to respect the privacy of the victims and their families. He also said the fire department will set up a website where donations can be made.

With files from The Associated Press