The mental health of suspected Montana gunman Michael Paul Brown, 45, declined significantly following the death of his mother, relatives said.

On Monday, the U.S. Marshal Service posted on X that a reward of up to $10,000 would be offered for any information leading to Brown. The agency has also set up a tipline at: 1-8-77-WANTED-2.

The search for a former U.S. soldier suspected of killing four people at a bar in Montana stretched into a fourth day Monday, with deputies scouring the mountainous terrain by foot and air after the man escaped in a stolen vehicle containing camping gear.