No.
Let me ask you this; do you believe it is possible that Oswald was not on 10th street?
No. Absolutely not possible.
The best possible
combination of evidence that could possibly exist (lacking a confession from the killer) does, indeed, exist in the Tippit murder case --- i.e.,
(1) more than half-a-dozen witnesses who positively identified Oswald as either the killer of Tippit or as the man who was leaving the scene of the shooting holding a gun and
(2) the culprit being caught with the murder weapon in his very own hands at the time of his arrest (which was just half-an-hour after Officer Tippit was gunned down).
You couldn't get a better "evidence combination" to prove that Lee Harvey Oswald killed J.D. Tippit.
CTers will argue that there's "no evidence" at all against Oswald for Tippit's slaying. And they'll argue that they think the cops tampered with the shells AND did a switch-a-roo with the revolver.
But where's the PROOF that ANY evidence WAS tampered with? Do the CTers have any such PROOF? Of course they don't.