CHELSEA — Some on Warren Avenue hit the floor when they heard the gunshots. Others peered out the window nervously, watching as a man allegedly chased a woman and child into the street, exchanged gunfire with police, and eventually set his house ablaze.
The confrontation that set the area on edge Monday night finally ended early Tuesday, when authorities found Kelly Pastrana, 38, dead with a gunshot wound to his stomach and injuries from the fire that destroyed his home, authorities said.
As neighbors sought to return to normal, family members of Pastrana and law enforcement officials were trying to make sense of what had happened.
Suffolk District Attorney Daniel F. Conley’s office is investigating whether Pastrana shot himself or had been hit in a volley with police.
The investigation will determine “exactly what took place and whether criminal charges are warranted against anyone,” Conley said at an afternoon news conference held alongside Chelsea Police Chief Brian Kyes and other public safety officials.
Authorities described a dangerous scene that unfolded quickly starting about 9:30 p.m. Monday and that began with a domestic dispute that involved Pastrana, his girlfriend, and their young daughter.
Conley said the situation “escalated into an armed assault” in which Pastrana chased his girlfriend and their daughter to a neighbor’s house, where they sought shelter. Pastrana shot at that home, but the gunfire didn’t hit anybody.
Pastrana made his way back toward his home as the first Chelsea police officer arrived, summoned by neighbors who had heard the commotion.
Pastrana, who police said did not have a gun license, and the police officer exchanged gunfire outside, and the officer suffered a minor injury but remained on the scene.
The officer is on leave pending the investigation, according to Kyes.
Pastrana went into the home, authorities said, ignoring police attempts to negotiate.
Shortly after the standoff began, State Police said, Chelsea police issued an “all-out request for mutual aid assistance” and surrounding communities quickly sent reinforcements.
The police force set up a perimeter around the home and ordered neighbors to evacuate.
State Police spokesman David Procopio said there was another exchange of gunfire after the suspect shot at police from a window.
Eventually, the home was consumed by fire, which investigators believe Pastrana set. The danger posed by an unpredictable suspect made it hard for firefighters to battle the flames, so they focused on preventing fire from spreading to other homes.
Police went into the building just after 2 a.m. and located Pastrana’s body.
Family members said Tuesday they were stunned by what had happened.
A cousin and sister of Pastrana knelt Tuesday afternoon in front of the ruined structure, its melted siding peeling, its tidy shrubs still clinging to spring flowers.
Cousin Emanuel Santiago Ortiz said the incident did not represent the Pastrana he knew.
He said Pastrana had been having family problems, which Santiago Ortiz declined to discuss, and some financial distress.
But he said he could never have predicted anything like what happened Monday night.
The two had just been discussing getting together to play dominos and have a family visit.
“I just think in that moment, he didn’t have control of his actions,” Santiago Ortiz said.
He said Pastrana, who worked as a mover, had two children of his own and took care of three foster children. Only one daughter was home when the incident happened, police said.
On the normally peaceful street in a hilly part of town overlooking Boston, few neighbors said they knew Pastrana well, but many who had seen him and his family around described them as friendly and helpful.
Rebecca Kebede, who lives in a condo building nearby, said the scene she witnessed suggested the actions of a person who had “lost it.”
Kebede had parked on the street just before the first shot was fired.
The incident left Kebede and her husband, Mekonen Tudese, worried about what might have happened if she had gotten home a little bit later.
“If he had the audacity to shoot at the police, that was a very scary situation,” Tudese said.
A teenage girl who lives next door said she heard the gunfire and hit the ground. Eventually, her family ran into the neighboring condo building, where they sheltered in a hallway until it was safe to go home.
She said neighbors in that building gave them food, drink, and clothes.
Even after she returned home, the girl said she remained shaken up: “I couldn’t go to sleep.”
John R. Ellement of the Globe staff contributed to this report. Andy Rosen can be reached at firstname.lastname@example.org.