Stymied by treacherous terrain and untamed wilderness, authorities are struggling to find an Army veteran suspected of killing four people at a Montana bar. But the difficult landscape isn’t the only challenge.

The suspect accused of fatally shooting four people at a Montana bar, who remains at large, struggled with mental health issues but was denied services from agencies that were supposed to help, according to his niece.

Officers are "unrelenting in their pursuit, working around the clock" to find him, Montana Gov. Greg Gianforte stressed at a news conference on Tuesday. "Rest assured, our brave men and women of law enforcement aren’t giving up."

The search for Michael Paul Brown, who is suspected of killing four people, entered its fifth day on Tuesday with Governor Gianforte taking larger action

The manhunt in Montana is on day 5 for a former U.S. Army soldier on the run days after he allegedly shot and killed four at a local bar in the southwest part of the Treasure State.

Montana Gov. Greg Gianforte on Tuesday signed an executive order freeing up more resources for local law enforcement as they searched a mountainous area for a former U.S. soldier suspected of killing four people at a bar last week.

The suspect in the quadruple killings, 45-year-old Michael Brown, remained a fugitive, officials told USA TODAY on Aug. 4.

The search for suspect Michael Paul Brown is still underway as law enforcement ramps up efforts to track him down.