Medics wait to gain access to the Cascade Mall after four people were shot dead in Burlington, Washington, U.S. September 24, 2016. Sgt Mark Francis/Washington State Patrol/Handout via Reuters

Medics wait to gain access to the Cascade Mall after four people were shot dead in Burlington, Washington, U.S. September 24, 2016. Sgt Mark Francis/Washington State Patrol/Handout via Reuters

Medics wait to gain access to the Cascade Mall after four people were shot dead in Burlington, Washington, U.S. September 24, 2016. Sgt Mark Francis/Washington State Patrol/Handout via Reuters

September 24, 2016 12:47 AM (UTC+8)