Is It Legal To Use Deadly Force On Trespassing Migrants In Texas?
The short answer is no but, you can IF certain conditions are met and defining those conditions is a super "gray" area.
Those conditions allowing a property owner to shoot trespassers ... be they illegally in the US or not ... are very specific yet, also very confusing and open to speculation at the same time.
By "open to speculation", I mean that the way you see the situation could be seen very differently by a cop, a judge, a jury or the law in general.
First, here is a "situation". You catch someone cutting through your fence to gain access to your property. (Property mind you ... not your actual home. Once someone breaks into your home, things change.)
Having ascertained they aren't your neighbors looking for a party or the caterers for the party or any otherwise "welcome" guest, you order them to leave and they refuse.
You still can't shoot. In Texas, the use of deadly force, even if someone is illegally on your property ... again, US citizen or not ... is tricky and can only be exercised if:
(1) he reasonably believes that it is necessary to use force to prevent or terminate the trespass; and (2) he reasonably believes deadly force is necessary to prevent the trespasser from committing certain crimes, such as arson, burglary, or robbery. - tiltingthescales.com
While the use of deadly force can be justified in some cases, someone simply being on your property without your permission isn't one of them.
Believing someone will damage something, steal something, hurt you or your family, etc, isn't necessarily grounds to shoot either. That depends on several different factors.
Basically, unless it's actually happening, you should pretty much just call the cops and wait.
PS: I looked this stuff up and trust the sources but, remember, I'm NOT a lawyer.