Montana authorities are actively searching for a 45-year-old U.S. Army veteran suspected of entering a bar and committing a cold-blooded shooting that resulted in four fatalities last week. The accused shooter, Michael Paul Brown, remained elusive as of Monday, with law enforcement continuing their efforts to track him down.

A press release from the Montana Attorney General’s Office indicates that around 10:30 a.m. on Friday, Brown allegedly entered The Owl Bar in Anaconda and began firing, resulting in the deaths of bartender Nancy Lauretta Kelley, aged 64, and three patrons: Daniel Edwin Baillie, aged 59; David Allen Leach, aged 70; and Tony Wayne Palm, aged 74.

The bar is about 250 miles west of Billings.

On Sunday, Attorney General Austin Knudsen conducted a press conference to provide an update on the ongoing search and share more details about the suspect.

Knudsen explained that the photograph of Brown, released by the state’s Department of Justice, depicted him “largely unclothed” in just his underwear. This image was taken shortly after the crime when Brown reportedly went to a nearby location to dispose of his clothes and some personal belongings.

Subsequently, Brown is alleged to have stolen a vehicle stocked with camping gear, likely enabling him to dress and flee the vicinity.

“At this point, we have every reason to believe the suspect is fully clothed, shoes on his feet, able to get around,” Knudsen said.

Brown was last seen at around noon on Friday when he was spotted by law enforcement and a brief chase ensued. However, Knudsen said there was “some confusion” due to two different while vehicles being involved in the pursuit and authorities could not detain Brown.

The AG said he was not sure if Brown knew the victims, but said that from what he had gathered, it seemed like Brown was “a regular” at The Owl Bar and “he literally lived next door” to the establishment.

“I think it’s likely that he knew the bartender and these patrons, which makes this even more heinous,” Knudsen said.

While Knudsen said it was possible that Brown, whom he described as being “unstable,” had already taken his own life, he said that authorities were operating under the assumption that Brown is “alive, well, armed, and extremely dangerous.”

The AG reportedly told NBC News that investigators had recovered the car Brown allegedly stole, which led them to believe that the suspect was “very likely up in the mountains, hiding in the timber, in the cover somewhere.”

According to a report from The Associated Press, Brown was an armor crewman who served in Iraq for about a year before he returned to the U.S. in March 2005. He then served in the Montana National Guard from 2006 until 2009.

Brown’s niece told the wire service that since his return from Iraq, her uncle had struggled with mental health issues and often does not know who, where, or even when he is.

Officials are offering a reward of $7,500 for information leading to Brown’s arrest.