Who is Trevor Slattery?

[first lines] Jackson Norris:
My name is Jackson Norris. Today will be the most important of my career: my final interview with the most infamous man in America. A man that the world thought was a terrorist called the Mandarin, but is now alleged to be nothing but an actor. Thus far, the subject has been evasive and apparently oblivious to the point of my work. In fact, he seems oblivious to pretty much everything, except his own growing celebrity status, because now the whole world knows his name... [Trevor walks down a hallway to cheers from the prisoners] Jackson Norris:
This is my last chance to get beyond his lies and excuses, to confront the subject with elements of his own past, in order to unlock the truth. Because we need to know, once and for all: who is Trevor Slattery?