Who's on second?

The situation as of late afternoon, early evening of November 22, 1963:

• Lee Oswald is in custody claiming to have been at the front entrance on the First Floor during the assassination and to have had a fleeting encounter with a police officer and Roy Truly as they rushed into the building.
• Detective Ed Hicks is telling the press about an incident involving Oswald and a cop at the front entrance of the building shortly after the shooting.
• Marrion Baker on record as having encountered a man walking away from the rear stairway several floors up the building.

So far, not a single reference anywhere to a Second Floor lunchroom.