The manhunt for the person who opened fire and killed four people at a Montana bar stretched into its fourth day Monday.

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 a former U.S. soldier suspected of killing four people at a Montana bar has stretched into a fourth day with no capture.