The fugitive Army veteran who allegedly shot and killed four people at a bar in Montana could return to the town where the "heinous" crime unfolded, posing a "concern for the public," the states attorney general is warning.The whereabouts of Michael Brown, 45, remain unknown Monday following the Friday morning shooting at The Owl Bar in Anaconda, which claimed the lives of residents Daniel Edwin Baillie, 59, Nancy Lauretta Kelley, 64, David Allen Leach, 70 andTony Wayne Palm, 74."We've got tremendous cooperation from Homeland Security, from our federal partners, the FBI, the U.S. Marshal Service. We want to find this guy. This is a dangerous individual who has committed an absolutely heinous crime against this community and these victims," Montana Attorney General Austin Knudsen said."Absolutely there [are] concerns he might come back into town.By all indications, 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 added.VICTIMS OF MONTANA BAR SHOOTING IDENTIFIED AS MANHUNT FOR MILITARY VETERAN SUSPECT CONTINUESAuthorities released a photo of Brown on Saturday, showing him barefoot and shirtless, walking down a flight of steps. The image depicted Brown wearing black shorts and fleeing after the shooting Friday, according to the state's Department of Criminal Investigation (DCI).It is unclear what led to the shooting, but Knudsen said investigators believedBrown used one of his own personal rifles in the attack."I want to offer our deepest and sincere condolences to the community of Anaconda and to the family and friends of these victims. This is just absolutely horrific," Knudsen said. "Something like we haven't seen in the state of Montana and thankfully we do not see these things very often in the state of Montana."MANHUNT INTENSIFIES FOR ARMY VETERAN SUSPECTED OF KILLING 4 IN BAR SHOOTING AFTER TRUCK FOUND ABANDONEDBrown was an armor crewman in the Army from January 2001 to May 2005, Army Public Affairs confirmed to Fox News Digital. He deployed to Iraq from February 2004 to March 2005 and left the service with the rank of sergeant.He also served as an armor crewman in the Montana National Guard from April 2006 to March 2009, officials said.Knudsen said at one point this weekend, over 250 boots were on the ground in the manhuntfor Brown."We're exploring every option here. Could he have committed suicide or be dead? Yep. But we are acting under the assumption that he is alive, well-armed, and extremely dangerous," Knudsen added.Fox News Digitals Greg Wehner and The Associated Press contributed to this report.