A man set fire to a home in Tucson before engaging in a deadly shooting spree Sunday that left one neighbor dead and two first responders and a fire captain wounded before a police officer managed to neutralize the suspect and prevent any further loss of life, police say.

The suspect, identified by authorities as 35-year-old Leslie Stephen Scarlett, remained hospitalized in extremely critical condition as of Monday, Tucson Police Chief Chris Magnus said at a press conference. Investigators believe that Scarlett first set fire to a home at 3:46 p.m. Sunday. 

A woman who lived there is presumed dead, as yet-to-be identified remains were found badly burned at the scene, Fox News reports.

"Mr. Scarlett has a criminal history that includes serving six years in prison for armed robbery. He also has a history of mental health issues," Magnus said.

After setting the home ablaze, Scarlett left the scene and headed to a nearby park, where he ambushed two emergency responders who had been standing outside an ambulance stationed at Quincie Douglas Center for "an unrelated medical emergency," Magnus said. 

A 20-year-old male EMT who was shot in the head remained hospitalized in life-threatening condition, Magnus said. His 22-year-old female EMT partner, who was shot in the chest and an arm, remained hospitalized in serious but stable condition. 

Scarlett returned to the scene of the house fire, where he then opened fire on firefighters, neighbors and "basically anyone who was trying to help," Magnus said, adding that the suspect fatally shot one neighbor. 

A captain with the Tucson Fire Department, who was shot in an arm, was treated and released. A second neighbor who was grazed in the head by a round fired by the suspect "did not require further medical treatment at the hospital," Magnus said. 

Scarlett then left the scene of the house fire a second time, before ramming a police car that was responding to the incident, Magnus said. The driver, identified as Officer Danny Leon, an eight-year veteran of the Tucson Police Department, immediately got out and took cover. The suspect fired three rounds at the officer, who returned fire, striking Scarlett, Magnus said.