All I'm going to tell you is investigations, whether it be this and others, where you have partial facts, analysts, agents are always trying to interpret what those facts mean, extrapolate from them what they mean.

I would say in just about every investigation we have, there will be differences of opinion, where you have partial facts, as to what those facts mean.

They're - FBI agents are some of the finest people you'll find anyplace in the country or the world. And I'm lucky to have the opportunity to work with them.

In the United States, it's the mandate of the FBI to gather information relating to terrorism, go out and collect it, to do the interviews, to do the investigative work.

I was in my office when - on 9/11. I think I had a number of meetings scheduled. I was just getting to know the bureau. And somebody walked in and said the first plane had - or a plane had struck the World Trade Center, one of the towers.

People talk about the Patriot Act that was passed immediately in the wake of September 11. What the Patriot Act did was break down the walls between the various agencies.

In the context of September 11, there were so many that lost their lives that - how do you single out one person? There were so many acts of heroism that day from so many people, whether it be firemen and police officers in New York and our agents also.