(AP) — Deputies spent Saturday traversing a rugged mountainous area of Montana with helicopters overhead as a manhunt for a military veteran suspected of fatally shooting four people at a bar stretched into a second day with no capture.

Michael Paul Brown, 45, fled The Owl Bar in the small town of Anaconda in a white pickup before ditching it at some point, according to Lee Johnson, administrator of the Montana Division of Criminal Investigation, which is overseeing the case. He urged residents late Friday to stay at home and remain on high alert.

Authorities released a photo of the suspect said to be taken as he fled after the shooting: Gaunt, barefoot and wearing nothing but black shorts, he is seen walking down what appears to be a flight of outdoor concrete steps.

“While law enforcement has not received reports of Brown harming any other individuals, he is believed to be armed, and he is extremely dangerous,” Johnson said.

The search was still focused on an area off Stumptown Road west of Anaconda, both on the ground and by air, and included multiple local, state, and federal agencies.

Anaconda-Deer Lodge Police Chief Bill Sather said Saturday that businesses in the area could open, but he urged caution.

Authorities said they would release the names of the victims once all of their families have been notified.

“This is a small, tight-knit community that has been harmed by the heinous actions of one individual who does not represent what this community or Montanans stand for,” Johnson said.

Anaconda, about 25 miles (40 kilometers) northwest of Butte, is home to roughly 9,000 people. Hemmed in by mountains, it was founded by copper barons who profited from nearby mines in the late 1800s. A smelter stack that is no longer operational looms over the valley.

Brown lived next door to The Owl Bar, according to owner David Gwerder, who was not there when the shooting happened Friday morning. Gwerder told The Associated Press that the bartender and three patrons were killed, and he did not think anyone else was inside. He was not aware of any conflicts between Brown and the victims.

“He knew everybody that was in that bar. I guarantee you that,” Gwerder said. “He didn’t have any running dispute with any of them. I just think he snapped.”

Brown served in the Army as an armor crewman from 2001 to 2005 and deployed to Iraq from early 2004 until March 2005, according to Lt. Col. Ruth Castro, an Army spokesperson. Brown was in the Montana National Guard from 2006 to March 2009, Castro said, and left military service at the rank of sergeant.

Brown’s niece, Clare Boyle, told AP her uncle has struggled with mental illness for years and she and other family members repeatedly sought help.

“This isn’t just a drunk/high man going wild,” she said in a Facebook message. “It’s a sick man who doesn’t know who he is sometimes and frequently doesn’t know where or when he is either.”

A lockdown of the Stumptown Road area was lifted on Saturday.

A helicopter hovered over a nearby mountainside as officers moved among the trees, said Randy Clark, a retired police officer who lives there.

Word of the shooting spread through the town after it took place, and business owners locked their doors and sheltered inside with customers.