
Are you suggesting that Mr. Truly found Oswald at a location that suggested he was trying to leave the building? How do you figure?
If Officer Baker and Mr. Truly passed by an assassin who murdered the President and immediately tried to leave the building, they would have met such a person near the stairs and near the second floor. Perhaps on the first floor. Perhaps on the third. But near there.
The only person Officer Baker and Mr. Truly near this location just happened to be Oswald.
There is no other location. An assassin could come down the elevator, but they would know it was operating. There is only one set of stairs from the upper floor down to the second floor. Mr. Truly knew the building and would know all of that. Only by jumping out a window could an assassin attempting to flee the building immediately and not cross paths with Officer Baker and Mr. Truly.