New York shooter William Spengler lured firefighters to their deaths (VIDEO)

William Spengler killed himself after the ambush.</p>

William Spengler killed himself after the ambush.

The gunman who lured firefighters to their deaths on Christmas Eve apparently left a chilling note making his intentions clear: "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."

After setting fire to his house and car in Webster, New York, William Spengler lay in wait for the first responders to arrive and then opened fire in what Webster Police Chief Gerald Pickering described as a "clear ambush," NBC reported. 

The 62-year-old convicted felon, who had been previously jailed for killing his grandmother, shot and killed two firefighters and injured another two, before turning the gun on himself. 

The Associated Press said the ambush took place near Lake Ontario, just northeast of Rochester. 

One of the three guns used in the attack was a semi-automatic Bushmaster rifle, the same type of gun Adam Lanza used to massacre 20 children and six teachers at the Sandy Hook Elementary School in Newtown, Connecticut, on December 14, Sky News reported. 

"These people get up in the middle of the night to fight fires. They don’t expect to be shot and killed," said Pickering, according to The Democrat and Chronicle.

ITV identified the firefighters who were shot dead as Lt. Mike Chiapperini and Tomasz Kaczowka. Theodore Scardino and Joseph Hofsetter were expected to survive despite suffering "significant" injuries, Sky News said. 

The two firefighters who were rushed to Strong Memorial Hospital, remain in "guarded" condition, a hospital spokeswoman told Reuters. A third victim, an off-duty police officer, was hit by stray gunfire as he arrived to help.

Fire crews were called to the scene just after 5:30 a.m. Rob Bouitillier, the town's fire marshal said that the firefighters were shot at immediately after leaving their vehicle.

The gunfire stopped firefighters from battling the blaze for hours, and police SWAT teams had to evacuate homes in the area. 

Seven homes were destroyed by the fire, according to the BBC. Another two are inhabitable, NBC said.

The Monroe County's Sheriffs' office said that fire crews began to tackle the fire again after 10 a.m.  

New York Governor Andrew Cuomo said in a statement: "All of our thoughts and prayers go to the families and friends of those who were killed in this senseless act of violence."

New York Attorney General Eric Schneiderman said: "The contributions made by the fallen and injured officers in Webster will never be forgotten.

Webster was released on parole in 1998 after serving a 17-year sentence for beating his 92-year-old grandmother to death in 1980, NBC said. He shared the home with his sister, Cheryl, who he reportedly hated and is now missing. 

While a typewritten note made Spengler's intentions clear, his motive is not. 

Watch the AP footage from the scene:

Here is a clip from a police briefing:

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