There were two shooters when Kennedy was assassinated. They acted independently, but he was shot twice. The second one was on the grassy knoll and was hired by the mafia.
I fully believe this one. It’s what led me to generally think that most “conspiracy theories” (in quotes to denote the more pop-culture use of the term) probably have way more boring stories behind them. Like the idea that we actually did go to the moon, but filmed an enactment on a soundstage just in case the broadcast didn’t actually work, and that bit got out which leads to the wider conspiracy.
These are actually pretty good. What are the chances of two shooters getting the idea to shoot the presidential motorcade as it slowed down to turn a corner, with that long straightaway? I would say pretty good. They could have both "seen the shot".