The most plausible two shooters theory I’ve heard, basically states the second shooter was a secret service agent who accidentally/negligently discharged his weapon from the car behind JFK trying to engage the shooter from the school book depository…… however the accidental shot hit JFK in the back of the head with his new AR-15 a book was written about it; the secret service and the agent he named sued the book out of print.
Example of the evidence given….
AR-15 was a brand new weapon for the SS and was removed from the approved weapons list the week after JFK was killed.
The entrance hole in the back of JFK’s head was measured at 6mm, too small for the 6.5mm rifle Oswald used; but perfectly consistent with the 5.56mm when you consider “blow through” of bone upon bullet entry.
The “kill shot” or violent reaction head shot shown in the video is consistent with the wounds from a 5.56 bullets that were unstable with the twist rate of the first generation AR-15.
So the conspiracy was covering up the secret service accidentally killing the president.