It is a reasonable standard and prerequisite if the two “researchers” want anyone to believe them.
If that’s the case (and I tend to agree) then why aren’t you applying the same standard to the anonymous FBI letter writer? In that case, there isn’t even anybody to challenge. IMHO by design.
No double standard. C2011 is an official FBI document written by the Dallas Office of the FBI.
So that makes it somehow immune to equal scrutiny?
It was admitted into evidence by the WC.
Without any scrutiny, it seems. Does the WC’s deference to the FBI somehow make this letter authenticated in any way?
Weak, uncorroborated thirdhand hearsay is weak, uncorroborated, thirdhand hearsay. Regardless of the source.
Your innuendo that it is somehow tainted is pure speculation. A jury could not consider speculation.
Reasonable doubt doesn’t require proof of tampering. Or speculation.