Washington State Patrol handout via Reuters
The Washington State Patrol in a message on Twitter also confirmed a person had been taken into custody.
Authorities first received reports of shots fired in Burlington's Cascade Mall around 7 p.m. PT on Friday night.
A gunman had opened fire in a Macy's store, killing four women and a man. The suspect remained at large for nearly a full day as authorities launched their search.
(Reporting by Alex Dobuzinskis in Los Angeles and Curtis Skinner in San Francisco; Editing by Michael Perry)