King County could require stores that sell guns to post signs at the door and cash register warning that owning a firearm increases the risk of suicide, homicide and other deaths. Metropolitan King County Council Chairman Joe McDermott is proposing the new regulation, which would be enacted and enforced by the King County Board of Health. The measure is the latest in a series advanced by local politicians and activists who say gun violence is a public-health crisis and should be dealt with as such.Washington State Initiative 1639, which is likely to appear on the November ballot, would require gun-purchase...