This is a really good article, shedding some new light on what happened Saturday. It looks to be mental health rather than politically motivated. It sounds like if Biden or another public figure was doing a rally or public event there instead, he would have gone after them.
A Blind Spot and a Lost Trail: How the Gunman Got So Close to Trump
https://www.nytimes.com/2024/07/17/...rump-shooting.html?smid=nytcore-android-share
"But in the aftermath, when the F.B.I. was able to finally access Mr. Crooks’s cellphones and other electronic devices,
agents could see that he had searched for images of Mr. Trump as well as President Biden, Attorney General Merrick B. Garland and even F.B.I. Director Christopher A. Wray.
Mr. Crooks also had at typed in “major depressive disorder” and searched for dates and places for appearances for both Mr. Biden and Mr. Trump.
One of Mr. Trump’s planned appearances happened to be about 50 miles from Mr. Crooks’s house in Bethel Park, Pa.
On Friday, July 12, the day before the attempted assassination, Mr. Crooks went to a shooting range, according to an investigative summary prepared by the F.B.I. The next morning, he bought a ladder at a Home Depot and then later that day he purchased 50 rounds of ammunition from a gun shop near his home, according to the F.B.I. document and federal law enforcement officials."