A young GHW Bush told newly recruited asset Oswald, "Lee, I know you work in the school depository and are a good shot. Here's how you can help us. There are a couple of rogue CIA guys that want to shoot Kennedy when he comes to town. One will be on the grassy knoll here (points to map) and another will be here on the triple underpass. If you can take them out you'll be a hero and your wife can get citizenship. Our local guy Josh Rubinstein will help you get away"

GHWB keeps his mouth shut and the rest is history