Likely parts of domestic/foreign military intelligence apparatus. Who knows what the US government knew, and at what time? .... good questions for polygraph, before its too late and we will never know.
Now that scientifically irrefutable facts are known, everybody who disregards them, does not report them to authorities, is becoming part of a cover up of a serious crime, which is a crime in itself.
What does US government know now? They are ignoring serious evidence, it is no more possible that they do not know about it.
They have been served papers for example by www.walca.org, if not by others too. Even Vice President Biden in person was handed a scientific study proven the obvious fact - that 3 WTC towers were destryoed by controlled demolition.
www.ae911truth.org - www.twitter.com/911news - www.krunchd.com/911
A UN expert on human rights in the Palestinian territories on Friday denied that he endorsed claims of US government involvement in the September 11 attacks. I wish to be absolutely clear; I do not endorse the theory that the US government orchestrated the 9/11 attacks, Richard Falk said in a statem