William Lansing Downing (born August 1, 1949) is a judge of the Superior Court of Washington for King County (Seattle) and a former deputy prosecutor.
He is notable for his ruling that same-sex marriages are legal in Washington, as well as for the prosecutions of the Wah Mee massacre killers.In 1978, he graduated with a J.D.
from the University of Washington School of Law, along with classmate Robert S.