Crooks and his father belonged to the Clairton Sportsmen’s club close to their home. He’d probably been shooting for years.
https://www.cnn.com/2024/07/15/us/thomas-crooks-trump-rally-shooting-invs/index.html
I barely qualified with the M-16 while in the Marines. Yet I could hit a target of that size from that distance from a prone position.