RCW 11.84.140: Slayer determination—Conviction—Preponderance of evidence.

(1) A final judgment of conviction for the willful and unlawful killing of the decedent is conclusive for purposes of determining whether a person is a slayer under this section. A finding of not guilty by reason of insanity for the willful and unlawful killing of the decedent carries the same meaning as a judgment of conviction.

(2) In the absence of a criminal conviction or a finding of not guilty by reason of insanity, a superior court finding by a preponderance of the evidence that a person participated in the willful and unlawful killing of the decedent is conclusive for purposes of determining whether a person is a slayer under this section.