Judge Lum was appointed to the King County Superior Court bench in 1998 by Governor Gary Locke and is currently assigned to the criminal department. He previously has served on the Court's civil and juvenile calendars and was the Court's Chief Civil Judge and Chief Judge at the Maleng Regional Justice Center in Kent. Judge Lum is a Seattle native and a graduate of Franklin High School, Pomona College, and the University of Washington School of Law. After graduation, he served as a Deputy Prosecuting Attorney in the Criminal Division of the King County Prosecutor's Office for seven years, trying dozens of felony jury trials to verdict. From 1990 to 1998, he practiced complex civil litigation as a partner in several Seattle law firms and was a founding shareholder of Forsberg & Umlauf.
Judge Lum has been very active in local, state and national bar association and civic activities and is a frequent speaker on trial practice, insurance coverage, ethics, and diversity. He was the President of the Asian Bar Association of Washington (1992) and received the 2002 Trailblazer Award from the National Asian Pacific American Bar Association. He was a member of the Washington State Sentencing Guidelines Commission, the ABA's Standing Committee on Public Education, the Judge's Advisory Committee to the ABA's Standing Committee on Professional Responsibility and Ethics; was an Adjunct Professor at Seattle University School of Law; and is a past Dean of the Washington State Judicial College.
He currently serves on the ABA Commission on Immigration, the President's Minority Advisory Committee for the University of Washington, and the Board of the Washington State Superior Court Judge's Association. He chairs the National Adoption Day Celebration for King County and Washington State.