Before I get flamed for lack of cites.
RCW 9A.16.050
Homicide — By other person — When justifiable.
Homicide is also justifiable when committed either:
(1) In the lawful defense of the slayer, or his or her husband, wife, parent, child, brother, or sister, or of any other person in his or her presence or company, when there is reasonable ground to apprehend a design on the part of the person slain to commit a felony or to do some great personal injury to the slayer or to any such person, and there is imminent danger of such design being accomplished; or
(2) In the actual resistance of an attempt to commit a felony upon the slayer, in his or her presence, or upon or in a dwelling, or other place of abode, in which he or she is.
The use, attempt, or offer to use force upon or toward the person of another is not unlawful in the following cases:
(1) Whenever necessarily used by a public officer in the performance of a legal duty, or a person assisting the officer and acting under the officer's direction;
(2) Whenever necessarily used by a person arresting one who has committed a felony and delivering him or her to a public officer competent to receive him or her into custody;
(3) Whenever used by a party about to be injured, or by another lawfully aiding him or her, in preventing or attempting to prevent an offense against his or her person, or a malicious trespass, or other malicious interference with real or personal property lawfully in his or her possession, in case the force is not more than is necessary;
(4) Whenever reasonably used by a person to detain someone who enters or remains unlawfully in a building or on real property lawfully in the possession of such person, so long as such detention is reasonable in duration and manner to investigate the reason for the detained person's presence on the premises, and so long as the premises in question did not reasonably appear to be intended to be open to members of the public;
(5) Whenever used by a carrier of passengers or the carrier's authorized agent or servant, or other person assisting them at their request in expelling from a carriage, railway car, vessel, or other vehicle, a passenger who refuses to obey a lawful and reasonable regulation prescribed for the conduct of passengers, if such vehicle has first been stopped and the force used is not more than is necessary to expel the offender with reasonable regard to the offender's personal safety;
(6) Whenever used by any person to prevent a mentally ill, mentally incompetent, or mentally disabled person from committing an act dangerous to any person, or in enforcing necessary restraint for the protection or restoration to health of the person, during such period only as is necessary to obtain legal authority for the restraint or custody of the person.
RCW 9A.16.110
Defending against violent crime — Reimbursement.
(1) 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.
(2) When a person charged with a crime listed in subsection (1) of this section is found not guilty by reason of self-defense, the state of Washington shall reimburse the defendant for all reasonable costs, including loss of time, legal fees incurred, and other expenses involved in his or her defense. This reimbursement is not an independent cause of action. To award these reasonable costs the trier of fact must find that the defendant's claim of self-defense was sustained by a preponderance of the evidence. If the trier of fact makes a determination of self-defense, the judge shall determine the amount of the award.
(3) Notwithstanding a finding that a defendant's actions were justified by self-defense, if the trier of fact also determines that the defendant was engaged in criminal conduct substantially related to the events giving rise to the charges filed against the defendant the judge may deny or reduce the amount of the award. In determining the amount of the award, the judge shall also consider the seriousness of the initial criminal conduct.
Nothing in this section precludes the legislature from using the sundry claims process to grant an award where none was granted under this section or to grant a higher award than one granted under this section.
(4) Whenever the issue of self-defense under this section is decided by a judge, the judge shall consider the same questions as must be answered in the special verdict under subsection (4) [(5)] of this section.
(5) Whenever the issue of self-defense under this section has been submitted to a jury, and the jury has found the defendant not guilty, the court shall instruct the jury to return a special verdict in substantially the following form:
RCW 9.41.270
Weapons apparently capable of producing bodily harm — Unlawful carrying or handling — Penalty — Exceptions.
(1) It shall be unlawful for any person to carry, exhibit, display, or draw any firearm, dagger, sword, knife or other cutting or stabbing instrument, club, or any other weapon apparently capable of producing bodily harm, in a manner, under circumstances, and at a time and place that either manifests an intent to intimidate another or that warrants alarm for the safety of other persons.
(3) Subsection (1) of this section shall not apply to or affect the following:
(a) Any act committed by a person while in his or her place of abode or fixed place of business;
(b) Any person who by virtue of his or her office or public employment is vested by law with a duty to preserve public safety, maintain public order, or to make arrests for offenses, while in the performance of such duty;
(c) Any person acting for the purpose of protecting himself or herself against the use of presently threatened unlawful force by another, or for the purpose of protecting another against the use of such unlawful force by a third person;
Draw your own conclusions.
By that I would say that, yes, shooting back is perfectly legal.
