[burningyen]

I'm not a Texas lawyer, so this is not legal advice, etc. Here are what I believe are the applicable statutes, including the law that went into effect in September (the protection of property defenses don't apply because they only justify the use of deadly force at night):

§ 19.02. MURDER.
...
(b) A person commits an offense if he:
(1) intentionally or knowingly causes the death of an
individual;
(2) intends to cause serious bodily injury and commits
an act clearly dangerous to human life that causes the death of an
individual; ...

§ 9.31. SELF-DEFENSE.
(a) Except as provided in Subsection (b), a person is
justified in using force against another when and to the degree the
actor reasonably believes the force is immediately necessary
to protect the actor against the other's use or attempted
use of unlawful force. The actor's belief that the force was
immediately necessary as described by this subsection is presumed
to be reasonable if the actor:
(1) knew or had reason to believe that the person
against whom the force was used:
...
(C) was committing or attempting to commit
aggravated kidnapping, murder, sexual assault, aggravated sexual
assault, robbery, or aggravated robbery; [and]
(2) did not provoke the person against whom the force
was used;
...
(b) The use of force against another is not justified:
...
(4) if the actor provoked the other's use or attempted
use of unlawful force,
...
(e) A person who has a right to be present at the location
where the force is used, [and] who has not provoked the person against
whom the force is used, ... is not required to retreat before
using force as described by this section.

§ 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.
...
(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.
...