The truth will be filtered out by this technology.
The "truth" hasn't been ascertained already?
Your approach is subjective, insulting, and is highly suggestive of a person who's never been close to tragedy before.
It's highly callous, unscientific, and prone to fraud.
The folks who needed to make statements have done so, years ago.
Their memories have been dealt with, however they deal with things.
You want to go ripping all that mental scar tissue open for some science fair project?
How about some goddamned common decency? Ethics? Are this concepts with which you are familiar?
You're premise is flawed anyway. I'd predict that were you even able to set this up you would have a very low number of actual event witnesses participating. It'd be bored internet kiddies and truthers trying to push their pet theory. The only amusing thing would be for your program to continually crash due to a lack of consensus in your "witnesses."
But by all means, go right ahead. Attempt to contact some members of the FDNY who pulled bits of spinal cord and severed limbs out of rubble, digging for some kind of life to save. You go right ahead an do that. Just be sure to post pictures of the shiner you're bound to receive.
"Shiner" - American slang for a black eye
"Black Eye" - American slang for getting punched the **** out