A manhunt is intensifying for the gunman who allegedly killed a bartender and three patrons at a bar in southwestern Montana, authorities said.

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.

As the search for Michael Paul Brown continued, Montana Gov. Greg Gianforte signed an executive order freeing up more resources for local law enforcement.