There is an RCW that does state:
"No person in the state shall be placed in legal jeopardy of any kind whatsoever for protecting by any reasonable means necessary, himself or herself, his or her family, or his or her real or personal property, or for coming to the aid of another who is in imminent danger of or the victim of assault, robbery, kidnapping, arson, burglary, rape, murder, or any other violent crime as defined in RCW 9.94A.030"
but I don't remember what the actual RCW for that statement is.