RCW 25.10.711Proper plaintiff.A derivative action may be maintained only by a person that is a partner at the time the action is commenced and:(1) That was a partner when the conduct giving rise to the action occurred; or(2) Whose status as a partner devolved upon the person by operation of law or pursuant to the terms of the partnership agreement from a person that was a partner at the time of the conduct.[ 2009 c 188 s 1003.]
Washington Legal Code