If the ONLY evidence found was Oswald's prints on the boxes, then it might alone not be sufficient to prove his guilt. But taken within the totality of evidence, it is highly probative. To suggest that his prints being found on the SN boxes is "silly and irrelevant" tells us we are dealing with someone who is just playing defense attorney/devil's advocate and can't be taken seriously. Not that there was any prior doubt. When all is said and done, the evidence always points back to one person. All the more humorous is the notion espoused by these same parties that it is a "strawman" argument to suggest they are implying a conspiracy. Oswald was apparently just the unluckiest guy in history. Of all the TSBD employees, he is the only one to touch these particular boxes and the bag. He decides not to watch the motorcade like nearly every other employee and thus has no credible alibi. Somehow his rifle magically appears with his prints on it. He decides to knock off early for a movie and is the only person on planet Earth to be in the TSBD at the time of the assassination to pass the scene of the Tippit murder. The only Dallas PD officer murdered in a several year period. What are the odds that Oswald is at the scene of a presidential assassination and police murder within a one hour period? And he looks so much like the Tippit shooter that several witnesses identify him as the murderer. And he has a pistol with the same two brands of ammo used by the murderer. When he goes window shopping for some shoes, he attracts the suspicion a random salesman. Terrible luck. Then he decides to duck into the movie without buying a ticket. More bad luck. This results in the police being called on him while just wondering about in Mr. Magoo-like bliss. And instead of just answering their questions he decides to put up a fight. And on and on. But this is all "silly and irrelevant." Nothing to see here. Just an incredible series of bad luck and random citizens all lying for no apparent reason to implicate him.