How come you don't post this tidbit from the article you cited?
"I think he came here with a purpose and a mission," Freeman Martin, regional commander of the state Department of Public Safety, said at a news conference Monday evening.
Martin disclosed that at least 15 empty 30-round ammunition magazines were found at the church, along with "hundreds" of shell casings" — more than he would ever need, Freeman said, to "take care of the mother-in-law."
Twenty-three people were killed inside the sanctuary, Martin said, adding that authorities have "a video recording from inside the church." Two more people were killed outside the building, and one person died later at a hospital.
Kelley was found dead after the massacre in his vehicle — apparently from a self-inflicted gunshot wound, Martin said. A Glock and a Ruger handgun were found inside the Ford Expedition he had been driving, and a Ruger AR-556 rifle was recovered at the church, Martin said.
Kelley, who was 26 and lived in nearby New Braunfels, had been wounded earlier when he got into a gunfight outside the church with a man who lived nearby and was armed with at AR-15 assault-type rife, Martin said.
Martin didn't identify the "hero Texan" who traded shots with Kelley, whose body was found with three gunshot wounds, "two from the citizen, one apparently self-inflicted."
He said that as Kelley raced away from the crime scene, "the suspect did notify his father that he had been shot and that he was not going to make it."
https://www.nbcnews.com/storyline/texas-church-shooting/texas-church-shooter-may-have-been-targeting-his-mother-law-n817961