(AP) — The former U.S. soldier suspected of killing four people at a Montana bar was still at large early Sunday and may be armed after escaping in a stolen vehicle containing clothes and camping gear, officials said.

Authorities believe 45-year-old Michael Paul Brown killed four people on Friday morning at The Owl Bar in Anaconda, Montana, about 75 miles (120 kilometers) southeast of Missoula in a valley hemmed in by mountains.

Montana Attorney General Austin Knudsen said at a news conference Sunday that Brown committed the shooting with a rifle that law enforcement believes was his personal weapon.

The victims ranged in age from 59 to 74 and were a female bartender and three male patrons.

Knudsen warned residents in the town of just over 9,000 people that Brown, who lived next door to the bar where he was a regular, could come back to the area.

“This is an unstable individual who walked in and murdered four people in cold blood for no reason whatsoever. So there absolutely is concern for the public,” Knudsen said.

Numerous public events were canceled over the weekend as the search entered its third day, according to local Facebook pages.

Robert Wyatt, 70, said he was neighbors with 70-year-old David Allen Leach, one of the three bar patrons killed on Friday morning.

The two men lived next door to each other in a public housing complex for elderly people and people with disabilities.

“Everybody is nervous” since Friday, Wyatt said. Leach was deaf and kept mostly to himself, Wyatt said, and he only recalls Leach having a family visit once almost a year ago. But Leach was always happy to help his neighbors with chores like moving furniture.

“If you needed help, Dave would help,” Wyatt said. “He was a good neighbor.”

Investigators are considering all possible options for Brown’s whereabouts, the attorney general said. That includes searching the woods where Brown hunted and camped while he was a kid. But Knudsen noted that during peak tourist season in western Montana some law enforcement officials would have to return to their local jurisdictions for their regular responsibilities.

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, Castro said, and left military service at the rank of sergeant.

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.

“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.”