rickyrick said:
Many states, use of force is justifiable to protect property. Even in your front yard.
Doyle said:
Actually, just the opposite. Texas seems to be unique in that it allows use of force to protect property.
Actually' y'all are
both oversimplifying the matter.
In most states, including many so-called anti-gun ones, it is lawful to use force to prevent the imminent commission of a felony offense or to detain someone who has committed a felony offense; needless to say, some classes of property crimes are felonies. Force is also generally allowable against a person committing criminal trespass, particularly when the person using the force owns or legally controls the land, home, or business being trespassed upon, and/or there is reasonable cause to believe that the trespasser has criminal intent. The conditions under which the force may lawfully escalate to
deadly force vary, but it's allowable in most places under certain conditions.
The WA Criminal Code has
this to say about the matter, my emphasis underlined:
RCW 9A.16.020
Use of force — When lawful.
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.
[1986 c 149 § 2; 1979 ex.s. c 244 § 7; 1977 ex.s. c 80 § 13; 1975 1st ex.s. c 260 § 9A.16.020.
In short, it's lawful under certain conditions to WA to use force (a) to detain someone who has committed a felony, (b) to prevent "a malicious trespass, or other malicious interference with real or personal property," albeit with the condition that "the force is not more than is necessary," or (c) "to detain someone who enters or remains unlawfully in a building or on real property".
I don't know enough to comment on whether any of the actions Mr. Barton undertook rose to the level at which
deadly force would be considered defensible in protection of his property. However, it's clear that
some level of force is legally justifiable in WA under certain circumstances when defending property. The fact that prosecutors dropped the gun charges against Mr. Barton implies that there was
some possibility - however remote - that the requisite conditions for lawful use of deadly force to protect property may have been met.
Finally, the unique thing about TX law is that it's lawful under certain specific circumstances to use deadly force to RECOVER stolen property, even when the suspect is already fleeing, and when there is no particular indication that the theft rises to the level of a felony.
Mandatory disclaimer: I am not an attorney, nor do I play one on TV. 
This is not legal advice. Caveat emptor and YMMV.
