Other than a time machine it is difficult to understand how there could be any more evidence of the fact. What do you believe is lacking? The shots were fired from the 6th floor window at 12:30. Fired bullet casings from a rifle belonging to Oswald were found by that window. Oswald's prints are on the SN boxes. His prints are on a long bag found near that window. His rifle is left on that floor. He has no credible alibi, flees the building within minutes, kills a police officer and lies to the police about the rifle and many other things. It is a drumbeat of guilt. Criminals take measures to avoid detection while committing the act. Not every crime is captured on film. That does not create any doubt, however, when a mountain of evidence is left at the scene. Guilty.
"rifle belonging to Oswald" . LOL.
"long bag found near that window". LOL.
"flees the building". LOL.
"kills a police officer". LOL.
"lies to the police". LOL.
"guilt". LOL.
"mountain of evidence". LOL.