Thanks Jim. The running up the knoll by the spectators seems to start after officer Haygood gets off his bike and starts running up the knoll towards the fence and then the railway bridge over the underpass. Here is the Willis 6 photo about 80 seconds after the head shot showing Haygood starting his run with the knoll completely empty:
Cabluck 2 taken about 8 seconds later shows some teenage boys running across in front of the pergola with Haygood in the distance:
Then we have the Bond 6 photo taken about 100 seconds after the head shot which shows the knoll with all of the people running across it towards Haygood who is scrambling up the wall.
Lastly we have the Cancellare 3 photo 116 seconds after the head shot showing all of the boys and other curious spectators have clustered around Haygood on top of the wall:
All of these photos are depicted in the animation, and are shown as yellow flashes with the text in the top left explaining each of them (just press the pause button to catch them). The are some later films depicting an even larger swarm of people on the knoll but this was several minutes later and not captured in the animation. When I completed the animation I was surprised it took well over a minute for people to charge up the knoll, but this project has been full of surprises for me as I uncovered the exact timing sequence of events!
"Bowers and others saw a motorcycle officer dismount hurriedly and
come running up the incline on the north side of Elm Street. The
motorcycle officer, Clyde A. Haygood, saw no one running from the
railroad yards."
-- Warren Report
While the Report correctly identifies Haygood as the running policeman, they are probably wrong about Bowers having seen Haygood.
Bowers: At the time of the shooting there seemed to be
some commotion, and immediately following there was
a motorcycle policeman who shot nearly all of the way
to the top of the incline.
Ball: On his motorcycle?
Bowers: Yes.
Ball: Did he come by way of Elm Street?
Bowers: He was part of the motorcade and had left it for
some reason, which I did not know.
Ball: He came up---
Bowers: He came almost to the top and I believe
abandoned his motorcycle for a moment and then
got on it and proceeded, I don't know
Ball: How did he get up?
Bowers: He just shot up over the curb and up.
Ball: He didn't come then by way of Ell, which dead
ends there?
Bowers: No; he left the motorcade and came up the
incline on the motorcycle.
Ball: Was his motorcycle directed toward any
particular people?
Bowers: He came up into this area where there are
some trees, and where I had described the two men
were in the general vicinity of this.
Bowers is describing the short run by Officer Hargis to the corner of the retaining wall. Only Hargis didn't ride his motorcycle there; Bowers pictured that in his mind. It would be impossible for Bowers to see to where Haygood dismounted and ran up the knoll. Maybe after Haygood arrived at the abutment. Dale Myers determined that the "two men" Bowers refers to were in the area between the pergola's west shelter and the wooden fence, so Bowers could have seen Hargis' white helmet as he got to the retaining wall.
Haygood was a block away when he heard three shots. He passed the Newman family who were on the ground. He said: "Some of them were pointing back up to the railroad yard, and a couple of people were headed back up that way." When he returned to his cycle, he was told the shots came from the Depository.
"A motorcycle policeman, Clyde A. Haygood, dismounted in
the street and ran up the incline. He stated that he saw no
one running from the railroad yards adjacent to the overpass.
Subsequently, at 12:37 p.m., Haygood reported that the shots
had come from the Texas School Book Depository Building."
-- Warren Report
The man in the suit running on the sidewalk is NBC reporter Robert MacNeil. Richard Trask in "Pictures of the Pain" thought it might have been Dallas Morning News reporter Kent Biffle. MacNeil was in the same Press Bus as the photographer, Harry Calbuck, who was working for the Fort Worth Star-Telegram.
James Altgens is standing at the left edge of the Calbuck photo. This would be after he's taken his photo of Zapruder and Sitzman down off the pedestal, and himself having crossed the street.