Easy solutions...
1) Don't commit crimes, such as cocaine-related trade, and don't get yourself deported like Torres (one of the bad guys) did.
2) If you're deported, don't come back to the United States illegally (like Torres did).
3) If you do sneak into the country, don't rob other people's houses, and you're less likely to get shot.
Numbers 1 & 2 are completely irrelevant. The shooter didn't know either fact, and it's arguable whether it would have made a difference if he had. It's not a like a Tennessee vs. Gardner thing where you know the guy has just committed some heinous violent crime and is about to commit another one. And even if he did know the deceased were in the country illegally that's not usually a capital offense or even jailable in the real world.
Number 3 is the important one. I submit he would only have walked in Texas. Even in Oregon, which has pretty expansive self defense laws shooting someone who is running away from a burglary will get you in serious trouble unless he's leaving a trail of someone else's blood.
Frankly, the guy is lucky. He was a White middle-class homeowner. The dead were unemployed Central Americans. Just look at this quote:
Horn called 911 and told the dispatcher he had a shotgun and was going to kill the men. The dispatcher pleaded with him not to go outside, but Horn confronted the men with a 12-gauge shotgun and shot both in the back.
"he had a shotgun and was going to kill the men". Right there he blew his claim of self defense. He wasn't in danger. He wasn't preparing to defend himself. His intent was to
go out of his way to kill more than one person, leaving his home and exposing himself to extra risk in order to do so.
I'm as pro-armed defense as anyone. But this doesn't seem to have been self defense except by a very broad stretch of the term. Had I been the DA and had cared more about justice than political expedience I'd have convened a grand jury for manslaughter if not murder.
I'm glad that he was cleared of any charges. Had he not stopped those criminals, they would have certainly committed more crimes, and sooner or later, an innocent victim would have been killed.
You can't kill someone for what he might do some day and what might happen to some hypothetical person who isn't in immediate danger. That's not self defense. That's murder. He wasn't in danger. He wasn't protecting someone who was in danger. He wasn't interested in stopping people from committing a crime. He specifically wanted to kill people who were not an "immediate and otherwise unavoidable threat" to him.
The way I see it, he was protecting his neighbors, and under Texas Law, was justified in doing what he did.
He wasn't protecting the people in the house who had been burgled. The burglars were leaving.
He wasn't protecting people at large. He had no reason to believe anyone was going to die, be raped, have their home burned down around them or similar. He wasn't "protecting" anyone.