JayUtah
Penultimate Amazing
Where do I talk of human perfection?
When you established the standard that investigators were investigating the most important crimes of their careers and thereby would not have made any mistakes or departed in any way from what you deem proper police procedure. And then again when you insinuated that a person's memory of such an event would be especially reliable.
These are your conclusions, not mine.
Nope. They're your contrived standards. But if you'd now like to abandon your naive expectation along those lines, you may now proceed to show how the evidence supports coverup rather than human frailty as the most convincing explanation for the inconsistency you see in the evidence.
I do not know who killed JFK. If a person get convicted of murder and later found innocent on new evidence, let's say DNA-tests, do we have to know who the real killer is before we set the innocent free?
Apples and oranges. JFK conspiracy theorists constantly want to style their approach as a defense team exonerating Oswald. They adopt a legal approach that presumes Oswald was innocent, that rules of evidence apply, and that all they have to do is create reasonable doubt. That's not how history works. In an historical investigation you have to go farther than just casting murky doubt.
In the case of DNA, as in your analogy, we have to know that the killer is a different person than the convict, not merely that the DNA doesn't conclusively point to the convict. It does not matter whether that other person is identified so long as the test shows that he would be identifiable. That's how it works. DNA evidence of that form is affirmative exculpatory evidence, and the affirmative part of it still shoulders a burden of proof.
You are presenting an affirmative exculpatory theory, but you won't prove any of it.
There are no DNA-tests in the Oswald case, but all the alleged 'evidence' are tampered with...
"Tampered with" is your interpretation. The facts are as they are. Your interpretation of the facts is that the condition of evidence doesn't meet your expectations. There are two problems with that. First, your expectations are pure fantasy. Second, the explanation you offer pursuant to your interpretation is an affirmative claim of malfeasance for which you accept no burden of proof.
I have to start somewhere and I start with the bullet and the shells, mind you.
No. You think you have to start there in your carefully contrived plan, which is right out of the conspiracy theory playbook. The first step of your plan calls for you to set aside the conventional narrative in toto according to some begged absolute standard of proof, which you can only do by obsessing over insignificant detail that you pretend is crucial. Then you can promote your own hypothesis without any competition -- maybe even as the default which "must" hold after the conventional narrative is set aside.
In the real world you'd have to start by presenting your hypothesis, then going back and showing at each turn how your hypothesis better explains all the existing evidence, and requires fewer assumptions or untestable claims than the conventional narrative.