Yes, Tim has it right. That story is a hoax that originated on right-wing blogs. Seattle Times has the scoop: https://www.seattletimes.com/seattle-news/seattle-area-protests-updates-for-thursday-june-11/

If you’ll look closely, that Fox News article says, “…police say.” Indeed, it appears they are uncritically repeating what the police said, even though that statement has checked out to be false. (It would be nice if they would print a retraction but I won’t hold my breath.)