MOUNT RAINIER NATIONAL PARK, Wash. - Authorities in Washington state are asking people to stay away from Mount Rainier National Park and those already inside to leave as they search the snowy terrain for an armed gunman.

The Pierce County Sheriff's office says Benjamin Colton Barnes is a "strong person of interest" in the shooting death of a park ranger. Margaret Anderson was shot Sunday morning after stopping a vehicle that had sped through a park checkpoint.

Police say Barnes is also a suspect in the shooting of four people at a house party south of Seattle earlier Sunday morning.

Court documents show the Iraq war veteran was involved in a custody dispute in July and the toddler's mother sought a temporary restraining order against him. In an affidavit, the woman wrote that Barnes was suicidal and possibly suffered from post-traumatic stress disorder after deploying to Iraq in 2007-2008.

Authorities recovered Barnes' vehicle and found weapons and body armor inside. He's believed to have survivalist skills.

Search teams are scanning the park from aircraft equipped with heat-sensing capabilities.