One man was critically injured in the attack at the Cascade Mall in Burlington.
Washington State Patrol have described who they believe is the only gunman as a “Hispanic male wearing grey.”
Meanwhile a video has emerged of the moment a black man was shot dead by police in North Carolina.
The death of Keith Scott has led to protests in the city of Charlotte.
Police say he was armed.
In a video filmed by his wife – she pleads with officers not to shoot and can be heard telling them he's unarmed.
