Under Texas Penal Code §9.42, a person may use deadly force against another to protect land or property if:
1. He is the owner of the land;
2. He reasonably believes using the force is immediately necessary to prevent arson, burglary, or robbery; and
3. He reasonably believes that the land or property cannot be protected or recovered by any other means.
Thank you. The Texas law and doctrine is very similar to Florida, to my understanding. It's the right way to "ensure domestic tranquility", IMHO.