Crooks had a reasonably viable escape plan did not think he was going to get caught.
He was dressed like a what he felt was stereotypical red neck to blend in with the crowd.
He was planning on creating a panicked stampede of rally goers headed to the parking lot to escape by shooting up the stands after he blew Trumps head apart.
He would then detonate the bombs in the stampeding crowd to create mass casualty diversion that would allow him to escape using the bicycle he brought and parked near by
I thought it was amazing when Trump pointed out, at his RNC speech, that the crowd did not panic and run, but stayed there with him, even after hearing 8 shots. Again, God was at work.