Do you mean film of many people running up the knoll AFTER every single vehicle in the motorcade has passed through? How much time do you believe passed between the last shot and "many more people running up the grassy knoll"?
Marrion Baker is seen on film immediately running towards the front entrance of the building that deals with school books.
http://www.aarclibrary.org/publib/jfk/wc/wcvols/wh19/pdf/WH19_Decker_Ex_5323.pdfDECKER EXHIBIT No. 5323
-snip-
"As I heard the
first retort, I looked back over my shoulder and saw
what appeared to me to be a spray of water come out of
the rear seat of the President's car . At this same
moment, Mr. Lawson said, "Let's get out of here and
get to the nearest hospital". When I heard the shots
I noted motorcycle officers coming off their cycles
and running up the embankment on Dealey Plaza."-snip-
--------------------------
Before me, the undersigned authority, on this the 22nd day of November 23, 1963
personally appeared Hugh William Betzner, Jr . Address 5922 Velasco, Dallas
Age 22
-snip-
"Then the President's car sped on
under the underpass . Police and a lot of spectators started running up
the hill on the opposite side of the street from me to a fence of wood . I
assumed that that was where the shot was fired from at that time . I kept
watching the crowd."-snip-
--------------------------
Before me, the undersigned authority, on this the 22 day of November 22, l963
personally appeared S . M. Holland Address 1119 Lucille, Irvin
-snip-
"I looked over toward the arcade and trees and saw a puff of
smoke come from the trees and I heard three more shots after the first
Shot but that was the only puff of smoke I saw . I immediately ran around
to where I could see behind the arcade and did not see anyone running
from there . But the puff of smoke I saw definitely came from behind
the arcade through the trees."-snip-
--------------------------
Before me, the undersigned authority. on this the 22nd day of November 23, 1963
personally appeared William Eugene Newman
-snip-
"Then the car sped away and
everybody in that area had run upon top of that little mound . I thought the
shots had come from the garden directly behind me, that was on an elevation
from where I was as I was right on the curb. I do not recall looking toward
the Texas School Book Depository . I looked back in the vaccinity of the Garden."-snip-
-----------------------------------------
Before me, the undersigned authority. on this the 22nd day of November 1963
personally appeared Mr J.C. Price Address 9602 Astor, Dallas
"This day at about 1235 PM I was on the roof of the Termanel Annex Bldg on the
NE Corner when the presidential Motorcade came down Main to Houston, North on
Houston and then West on Elm. The cars had proceeded West on Elm and was
just a short distance from the Triple underpass, when I saw Gov Connelly
slump over . I did not see the president as his car had gotten out of my
view under the underpass . There was a volley of shots, I think five and then
much later, maybe as much as five minutes later another one . I saw one man
run towards the passenger cars on the railroad siding after the volley of shots.
This man had a white dress shirt, no tie and kahki colored trousers . His hair
appeared to be long and dark and his agility running could be about 25 yrs of
age. He had something in his hand."-snip-
----------------------------------------
Before me. the undersigned Authority, on this the 23rd day of November 1963
personally appeared Malcolm Summers.
"Yesterday, November 22, 1963, I was standing on the terrace of the
small park on Elm Street to watch the President's motorcade . The
President's car had just come up in front of me when I heard a shot
and saw the President slump down in the car and heard Mrs. Kennedy
say, "Oh, no" ., then a second shot and then I hit the ground as I
realized these were shots . Then all of the people started running
up the terrace away from the President's car and I got up and started
running also, not realizing what had happened . In just a few moments
the President's car sped off and everybody was just running around
towards the railroad tracks and I knew that they had somebody trapped
up there."-snip-
--------------------------------
COUNTY OF DALLAS
SHERIFF'S DEPARTMENT
SUPPLEMENTARY INVESTIGATION . REPORT
Name of Complainant
PRESIDENT JOHN F . KENNEDY
ASSASSINATION
-snip-
"I ran around the Corner and directly across the street across the Dealy
Plaza to the Elm street side of the triple underpass . As we were
running across the street, we could see the presidential car pulling away
under the underpass and we continued on to the immediate area. Some stopped
to talk to people standing there as there were a number of women who
were hysterical. We could not get any information except that the
President had been shot, Several of the other officers in the group ran
on into the freight yards."-snip-
----------------------------
ASSASSINATION OF PRESIDENT KENNEDY
COUNTY OF DALLAS
SHERIFF'S DEPARTMENT
SUPPLEMENTARY INVESTIGATION REPORT
Officer A . D. McCurley, Deputy Sheriff, Dallas County Sheriff's Office .
Ralph Walters
"I heard a retort and immediately recognized it as the sound of a rifle. I started running around the corner where I knew the
President's car should be and in a matter of a few seconds heard a second shot and then a third shot, I, along with other
officers who had been standing near me, all started running and I rushed towards the park and saw people running towards
the railroad yards beyond Elm street..."-snip-
http://www.aarclibrary.org/publib/jfk/wc/wcvols/wh19/pdf/WH19_Decker_Ex_5323.pdf