Mr Graves,
Alan is suffice. Given the mention/reference to a Texas Highway Patrolman in that page 15 quote I shared previously, I'm left to wonder if the driver of Vice-President Johnson's car, Texas Highway Patrol Joe Henry Rich weighed in with that 50 seconds.
Of course, in fairness to researchers like the late Mr. Marrs (Jim, RIP): Mr. Weisberg (Harold, RIP); and Mr. Palamara (Vince), it would be worthwhile to read anything they have authored about witnesses who actually saw the limo come to a stop. Include researcher Greg Burnham as well because I believe he cites none other than CBS News Anchor Walter Cronkite reporting the limo coming to a complete stop.
There is even an instance, where Hugh Betzer, in a same day 11/22/63 Sheriff's Dept. affidavit mentions multiple times within that document the limo came to a stop. The point here sir is that what really happened that fateful afternoon has been tainted by a hastily contrived script amid a bogus timeline sequence of events and "evidence" to frame the wrongly accused.
Appreciate the question. but in fairness to the OP, Mr. Ford, I respectfully move we return our chief focus back to the theme of the thread., "Is This Our Man?"
Lots going on behind that picket fence during the immediate aftermath of the treasonous ambush of a duly elected representative of the people.