Sad story, but dear Lord.... the troopers wear bow ties in WA??? Has to be one of those "The Western side of the State" has way to much control things.....
The reason for the bow ties is they give a professional look and if you get in an altercation with a suspect and you were wearing a tie it would give the perp something to grab onto. Also they are only worn with long sleeve attire which is usually winter wear unless otherwise specified.
