There was a “video game” that recreated the assassination from Oswald’s view. It was supposed to be a very accurate representation, ballistics wise, etc. They had a contest and gave a prize for the person coming closest to the timing and wounds of the event. Having some experience with rifles it was pretty apparant that the shots wouldn’t have been as hard as one might think. What I wondered was why he didn’t take out the driver as the car came toward him and then pick off everyone else in the car. I did that scenario and it worked out really well.
If the driver collapsed, the president would have been pushed to the floor with a pile of Secret Service agents on top of him.
The way to pick off the president is to pick off the president. Try to get clever, leave a few seconds' delay, and everyone moves to protect the president, and you just wind up braining Jim Brady.