Would it really provide comfort at all, to find that a nation's own leaders were even more vicious and murderous than those over-seas enemies they claim to protect you from?
I mean really, you wish to apply concepts of the ordinary (ie expected) to a day of extra-ordinary events?
I am sure there is plenty of scope for claim, counterclaim and sustained doubt, but such self-indulgence is to satisfy what?
There is so much we know we know and even more that we know we do not know (to channel an old man who should really be in jail right now (your cue MPD) so hold your 'independent' investigation, but there will forever be doubts regarding what ever is found to be 'true' and so seriously, why bother?
Let it go america.
Just coz you don't understand it
Doesn't mean it makes no sense!