Civil suits, however, are another matter.
In many states, including TX, once self-defense is successfully raised as a matter in court, the defender is/may be immune from civil liability as well. After all, the court found the defender was justified and therefore the act was the dead guy’s fault.
In MO, successfully inject the defense of justification (use of force in self-defense) the defender is immune from civil suit. Of course, it is the defender who must successfully inject the lawful self-defense argument in court, usually in a criminal trial.