The search for a former U.S. soldier suspected of killing four individuals at a bar in Montana extended into a fourth day on Monday. Deputies are actively searching the mountainous area both by foot and air after the suspect fled in a stolen vehicle equipped with camping gear.

Authorities have identified the suspect as Michael Paul Brown, 45, who allegedly used a rifle, believed to be his personal weapon, to fatally shoot four people Friday morning at The Owl Bar in the small town of Anaconda. Following the incident, he escaped in a white pickup, which he later abandoned, then stole a vehicle containing clothing, shoes, and other equipment.

The victims included a female bartender and three male customers. This tragic event has unsettled the close-knit community of about 9,000, keeping residents vigilant as the suspect has yet to be captured.

Here’s what is known about the search.

How is the search progressing?

Law enforcement from across the state has been mobilized to aid in the search for Brown, according to Montana Attorney General Austin Knudsen. The search effort includes various local, state, and federal agencies, utilizing both ground and aerial surveillance. Helicopters have been a constant presence over the weekend, as Anaconda’s residents adapt to life in the aftermath of the shooting.

The initial search efforts were focused near Stumptown Road, west of Anaconda. Knudsen noted that investigators are now exploring all potential clues regarding Brown’s whereabouts, including wooded areas where he is known to have hunted and camped in his earlier years. There are concerns he may be armed.

The woods southwest of Anaconda have been closed to the public by the National Forest System as the manhunt carries on.

On Friday, businesses secured their premises and took refuge with customers inside. Although the lockdown on the Stumptown Road area was lifted on Saturday, many local businesses have been slow to resume normal operations.

Who were the victims?

The victims were identified on Sunday as Daniel Edwin Baillie, 59, Nancy Lauretta Kelley, 64, David Allen Leach, 70, and Tony Wayne Palm, 74.

All four were residents of Anaconda, which is situated between rugged mountains about 25 miles (40 kilometers) northwest of Butte.

Robert Wyatt, 70, said he was neighbors with Leach at a public housing complex for elderly people and people with disabilities. Leach was deaf and kept mostly to himself, Wyatt said, but he was always happy to help his neighbors.

In a town where “everybody knows everybody,” the entire community is hurting, said resident David Jabarek, 70.

What is known about the suspect?

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

Brown lived next door to The Owl Bar, according to owner David Gwerder, who was not present during the shooting Friday morning. It was widely believed that Brown knew at least some of the victims.

In a photo released by law enforcement, Brown appears gaunt, barefoot and wearing nothing but black shorts.

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

He was known to local law enforcement before the shooting, Knudsen said. There is a $7,500 reward for any information leading to Brown’s capture.