The witnesses attending the lineups were NOT asked which man of the four most resembled the man they saw at the scene. No.
The witnesses were asked if the man they saw at the scene was any of the four men placed before them.
Mrs. MARKHAM. Well, let me tell you. I said the second man,
and they kept asking me which one, which one. I said, number two. When I said number two, I just got weak.
Asking her ?which one which one? is equivalent to asking her to pick the one who most resembled the man she saw.
We see manipulation with Callaway as well:
Mr. CALLAWAY. No. And he said, "We want to be sure, we want to try to wrap him up real tight on killing this officer. We think he is the same one that shot the President. But if we can wrap him up tight on killing this officer, we have got him."