How did they know to do this? How did they know that Oswald was on that bus...that transfer ticket? Come on :-\A smirk is 'hard evidence'?
The hard evidence is the bus transfer found in LHO's pocket.
Mr. McWatters. Well, they told me that they had a transfer that I had issued that was cut for Lamar Street at 1:00, and they wanted to know if I knew anything about it. And after I looked at the transfer and my punch, I said yes, that is the transfer I issued because it had my punch mark on it.
Mr. Ball. Did your punch mark have a distinctive mark?
Mr. McWatters. It had a distinctive mark and it is registered, in other words, all the drivers, every driver has a different punch mark.