For my 2c the Secret Service killed JFK while trying to protect him from Oswald. Two acoustics experts said there was a 95 percent certainty that the recording revealed that four shots had been fired at the presidential motorcade. Oswald fires once straight ahead but bullet fizzles. Oswald fires again misses and hits kerb. Another shot - the ' Magic Bullet " hits two targets, Gov and Potus. Fourth shot coincides with accidental firing of ' Dum Dum " round from SS car behind Potus. Gunpowder smell reported at ground level - Oswald was well above that and indoors! And no more neatly drilled Carcano holes -  a chuck of Potus head goes flying up in air before falling on trunk where Mrs K recovers it.  No CIA plot required where stupidity and insanity will cover it. Oswald's motives also possibly included ' South will rise again ' resentment against arch-Yankee, JFK and a large dollop of Marxist-Communism that started when O was 15 in NYC.  O saw himself as a left-fascist revolutionary and took a pot-shot at a local rightwinger before this. TL/DR Lee Harvey Oswald CAUSED the death which was then obfuscated to some extent by the US Secret Service.