Only know how to do links, sorry. It's John Lovett and Colion Noir on this.
Read a comment by a supposed Texas LEO who delt a lot wwith domestic issues. (Don't most?)
His take was that failure to comply with a Texas court order on custody is a low level felony. Therefore the cold guy was justified in being there and the ex-wife could be facing felony murder. Seeing as she was in the act of a felony that contributed to a death.
Hell if I know. No one can know what a jury will be told or do. But after watching the videos more, And listening to Lovett and Noir, Trespassing seems to be the key for defense. Dead guy just doesn't seem violent. Pised off? Oh, yeah!
Enough to become violent? Not really. If that was his nature, it would have shown before the gun came out. The gun is what ramped him up. Even then, he threatened to take it (normal dumbassery. Stupid dumbassery) but kept his hands down.
Hopefully, this stays in the public eye.
Parents who say they have good kids..Usually don't!