The gunman who killed three people and wounded six others as he fired randomly while roaming his northwestern New Mexico neighbourhood was a local high school student and his victims include a 97-year-old woman and her daughter, police said Tuesday.

Investigators were still trying to determine a motive for the attack by Beau Wilson, 18, in the Farmington neighbourhood where he lived. They say he opened fire on Monday, killing Gwendolyn Schofield, her 73-year-old daughter, Melody Ivie, and 79-year-old Shirley Voita.

Witnesses and police say Wilson walked through the neighbourhood a short drive from downtown Farmington spraying bullets until police arrived within minutes and fatally shot him. Two police officers were among the wounded.

“The amount of violence and brutality that these people faced is unconscionable to me,” Deputy Police Chief Kyle Dowdy said.

 “I don’t care what age you are, I don’t care what else is going on in your life, to kill three innocent elderly women that were just absolutely in no position to defend themselves is always going to be a tragedy.”

A bullet hole is seen through the bedroom window of Jolene Robledo's home . Photo / AP

Deputy Police Chief Baric Crum said Wilson was indiscriminately shooting at vehicles, but that some rounds also hit homes.

Dowdy said investigators do not believe Wilson knew anyone he shot.

“We’ve discovered nothing that leads us to believe that the suspect knew” the victims, he said. “We’re pretty confident in that this was completely random.”

In November, after he turned 18, Wilson legally purchased at least one gun used on Monday, police said. He carried three firearms in the attack, including an assault-style weapon.

Four officers fired a total of 16 rounds at Wilson, including one of the wounded officers, said San Juan County Sheriff Shane Ferrari.

Mayor Nate Duckett said Tuesday that the Farmington officer and state police officer were treated for their wounds and released from a hospital.

Authorities began receiving reports of gunshots at 10.57am and the first officer arrived at 11.02am, police Chief Steve Hebbe said. Three minutes later, the gunman had been killed.

Joseph Robledo, a 32-year-old tree trimmer, said he rushed home after learning that his wife, Jolene, and their year-old daughter had sought shelter in the laundry room when gunshots rang out. A bullet went through his daughter’s window, without hitting anyone.

Jolene Robledo said they had just finished breakfast when she heard “pop, pop, pop, pop,” which she first thought was a car backfiring. She said they were going to run out the back door until she heard a man curse right outside, so she quietly shut the door and hid with her daughter between the washing machine and dryer.

“I mean it was crazy. I called my husband and he could hear the gunshots over the phone,” she said. “He was freaking out and I was like, ‘don’t hang up, don’t hang up!’”

Joseph Robledo said he jumped a fence to get in through the back door. Out front, he found an older woman in the street who had been wounded while driving by. She appeared to have fallen out of her car, which kept rolling without her, he said.

“I went out to see because the lady was just lying in the road, and to figure just what the heck was going on,” Robledo said. He and others began to administer first aid.

Neighbours directed a police officer toward the suspect.

“We were telling [the officer], ‘He’s down there.’ … The cop just went straight into action,” Robledo said.

Robledo’s own family car was perforated with bullets.

A San Juan County sheriff's deputy cordons off a road following a deadly shooting. Photo / AP

“We’ve been doing yard work all last week. I just thank God that nobody was outside in front,” he said. “Obviously, elderly people — he didn’t have no sympathy for them.”

Downtown Farmington, a short drive from the neighbourhood, has undergone a transformation of sorts in recent years, with cafes and breweries cropping up alongside decades-old businesses that trade in Native American crafts from silver jewellery to wool weavings.

Nick Akins, a middle school teacher and resident, said it was “a great place to live”, with a mix of homes, short-term rental apartments and churches.

“You never think it’s going to happen here, and all of a sudden, in a tiny little town, it comes here,” Akins said.

On Tuesday, orange circles of spray paint still marked the ground where police had collected evidence. Authorities were using metal detectors to search the grass in front of one of the churches along the street where gunfire erupted.

As night approached on Monday, dozens of people gathered at Hills Church, a few kilometres from the attack scene, to pray at the base of a tall metal cross. Lead pastor Matt Mizell talked about living in a “dark and broken world” but told the crowd there was still hope and asked God to provide them strength.

Politicians also weighed in about the attack.

Duckett said in a statement that the shooting “has left us reeling in anguish and disbelief.”

Gov. Michelle Lujan Grisham said in a statement that she was praying for the families of those killed and that it “serves at yet another reminder of how gun violence destroys lives in our state and our country every single day”.

New Mexico enacted a red-flag law in 2020 that can be used to seize guns from people who pose a danger to others or themselves. Dowdy said relatives expressed concern about Wilson’s mental health when interviewed by police but that he didn’t have enough information at this time to further elaborate.

Rep. Teresa Leger Fernandez, a Democrat who represents the area in Congress, said in a Facebook post that “our beautiful Nuevo Mexico is not immune to the mass shootings that occur across the country — Every. Single. Day.”

“I praise the heroes who drove to danger to stop the violence. I pray for the quick recovery of the wounded and for the families of those we lost,” she said.