My question is not a strawman argument. I asked you to be patient regarding the peripheral conversation.
It is a reasonable question;
You stated that it was not unreasonable that the FBI had DNA evidence.
Back to MY question;
Where/how/when/or from whom did they, the FBI, or whoever was involved in identifying the hijackers obtain verifiable control samples?
I post again;
If the DNA of each hijacker was identified, from what, where and/or whom did they source the control DNA with which to compare?
I am sure you are all aware that in a criminal case, where DNA is used as evidence, control samples have to be used to confirm identification.
As an analogy, 'Mr Robber' breaks into the jewelers, whilst he is removing all the gold rings and placing them in his swag bag a fire breaks out, which quickly takes a very fierce hold and burns him to death. As you can imagine his remains are pretty gruesome and wholly unrecognisable.
The police have to identify him, they find traces of 'Mr Robbers' DNA at the scene, after identifying by verification and then ruling out all other DNA present, a slow but sure process. The DNA, in itself contain no clues to identity. To correctly identify 'Mr Robber' a previously verified control sample of DNA from a source which cannot be disputed, has to be used to, without a shadow of a doubt confirm his identity. Without this control sample, you just have A.N.Other's DNA.
I am not aware of any explanation for this. This is my question, ignore the surrounding peripherals of the interview.