Stymied by treacherous terrain and untamed wilderness, authorities are struggling to find an Army veteran suspected of killing four people at a Montana bar last week. Investigators say Michael Paul Brown,

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."

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.