The appeal to authority fallacy.
"Evidence" presented by two investigations is like evidence presented by a prosecutor who does not allow a defense counsel challenge it. It only has propaganda value.
And beyond The HSCA confirming
"Lee Harvey Oswald fired three shots at Kennedy. The second and third shots Oswald fired struck the President. The third shot he fired killed the President", as you previously argued the second investigation(HSCA) came to the conclusion there was a possible conspiracy, that doesn't sound like they(The HCSA) were relying on "propaganda value"!
JohnM