From Texas Penal Code:
http://www.texaspolicecentral.com/Penal_Code.pdf
Sec. 2.03. Defense.
(a) A defense to prosecution for an offense in this code is so labeled by the phrase: "It is a
defense to prosecution . . ."
(b) The prosecuting attorney is not required to negate the existence of a defense in the accusation
charging commission of the offense.
(c) The issue of the existence of a defense is not submitted to the jury unless evidence is admitted
supporting the defense.
(d) If the issue of the existence of a defense is submitted to the jury, the court shall charge that a
reasonable doubt on the issue requires that the defendant be acquitted.
(e) A ground of defense in a penal law that is not plainly labeled in accordance with this chapter
has the procedural and evidentiary consequences of a defense.
Sec. 2.04. Affirmative Defense.
(a) An affirmative defense in this code is so labeled by the phrase: "It is an affirmative defense to
prosecution . . . ."
(b) The prosecuting attorney is not required to negate the existence of an affirmative defense in
the accusation charging commission of the offense.
(c) The issue of the existence of an affirmative defense is not submitted to the jury unless
evidence is admitted supporting the defense.
(d) If the issue of the existence of an affirmative defense is submitted to the jury, the court shall
charge that the defendant must prove the affirmative defense by a preponderance of evidence.
Sec. 2.05. Presumption.
(a) Except as provided by Subsection (b), when this code or another penal law establishes a
presumption with respect to any fact, it has the following consequences:
(1) if there is sufficient evidence of the facts that give rise to the presumption, the issue of
the existence of the presumed fact must be submitted to the jury, unless the court is
satisfied that the evidence as a whole clearly precludes a finding beyond a reasonable
doubt of the presumed fact; and
(2) if the existence of the presumed fact is submitted to the jury, the court shall charge the
jury, in terms of the presumption and the specific element to which it applies, as follows:
(A) that the facts giving rise to the presumption must be proven beyond a
reasonable doubt;
(B) that if such facts are proven beyond a reasonable doubt the jury may find that
the element of the offense sought to be presumed exists, but it is not bound to so
find;
(C) that even though the jury may find the existence of such element, the state
must prove beyond a reasonable doubt each of the other elements of the offense
charged; and
(D) if the jury has a reasonable doubt as to the existence of a fact or facts giving
rise to the presumption, the presumption fails and the jury shall not consider the
presumption for any purpose.
(b) When this code or another penal law establishes a presumption in favor of the defendant with
respect to any fact, it has the following consequences:
(1) if there is sufficient evidence of the facts that give rise to the presumption, the issue of
the existence of the presumed fact must be submitted to the jury unless the court is
satisfied that the evidence as a whole clearly precludes a finding beyond a reasonable
doubt of the presumed fact; and
(2) if the existence of the presumed fact is submitted to the jury, the court shall charge the
jury, in terms of the presumption, that:
(A) the presumption applies unless the state proves beyond a reasonable doubt
that the facts giving rise to the presumption do not exist;
(B) if the state fails to prove beyond a reasonable doubt that the facts giving rise
to the presumption do not exist, the jury must find that the presumed fact exists;
(C) even though the jury may find that the presumed fact does not exist, the state
must prove beyond a reasonable doubt each of the elements of the offense
charged; and
(D) if the jury has a reasonable doubt as to whether the presumed fact exists, the
presumption applies and the jury must consider the presumed fact to exist
Sec. 9.32. Deadly Force in Defense of Person.
(a) A person is justified in using deadly force against another:
(1) if the actor would be justified in using force against the other under Section 9.31; and
(2) when and to the degree the actor reasonably believes the deadly force is immediately
necessary:
(A) to protect the actor against the other's use or attempted use of unlawful deadly
force; or
(B) to prevent the other's imminent commission of aggravated kidnapping,
murder, sexual assault, aggravated sexual assault, robbery, or aggravated robbery
(b) The actors belief under Subsection (a)(2) that the deadly force was immediately necessary as
described by that subdivision is presumed to be reasonable if the actor:
(1) knew or had reason to believe that the person against whom the deadly force was
used:
(A) unlawfully and with force entered, or was attempting to enter unlawfully and
with force, the actors occupied habitation, vehicle, or place of business or
employment;
(B) unlawfully and with force removed, or was attempting to remove unlawfully
and with force, the actor from the actors habitation, vehicle, or place of business
or employment; or
(C) was committing or attempting to commit an offense described by Subsection
(a)(2)(B);
(2) did not provoke the person against whom the force was used; and
(3) was not otherwise engaged in criminal activity, other than a Class C misdemeanor
that is a violation of a law or ordinance regulating traffic at the time the force was used.
(c) A person who has a right to be present at the location where the deadly force is used, who has
not provoked the person against whom the deadly force is used, and who is not engaged in
criminal activity at the time the deadly force is used is not required to retreat before using deadly
force as described by this section.
(d) For purposes of Subsection (a)(2), in determining whether an actor described by Subsection
(c) reasonably believed that the use of deadly force was necessary, a finder of fact may not
consider whether the actor failed to retreat.
