If it was a legitimate shoot (i. e. , in defense of life or property), the DA will send the case to a grand jury with his/her finding of justifiable homicide, the grand jury will no bill the shooter (so that the case can never be brought to criminal court again), and that will be the end of the criminal process.
Unfortunately, under civil law, one can just about sue anyone for anything, so the thief's family could theoretically sue the shooter for damages, but any Texas jury worth its salt isn't going to award damages for death sustained during criminal behavior.
Rusty