It appears that Thomas Crooks could've practiced at up to a 175 yard range at the Clairton Sportsmen's Club of which he was a member. It was a 20 minute drive from his house.

https://www.nytimes.com/2024/07/16/us/guns-crooks-pennsylvania-trump-shooting.html

According to George Webb this is a place where the Feds routinely practice Presidential assassination drills. If that's true, it would make it a convenient recruiting ground for a President shooting patsy.