I've seen a couple of videos where it's right after the murder and
there is a crowd in the street and there are 2 black teens in that
crowd. Don't know where the video is though. There is a picture of
the area from the air where Euins marked his position at first and
then when the shooting began. It's WC exhibit #365:
http://jfkassassination.net/russ/jfkinfo3/exhibits/ce365.jpg
Euins marked his first, second and third positions in black.
Chris