Bit of info about him from wiki
Though his performances of mind-reading and other feats of mentalism may appear to be the result of psychic or paranormal practices, he claims no such abilities and frequently denounces those who do.
Brown states at the beginning of his Trick of the Mind programmes that he achieves his results using a combination of "magic, suggestion, psychology, misdirection and showmanship"
This one was on last night
http://www.youtube.com/show?p=pz_Po3F-cCQ&tracker=show0
Basically, he does an experiment over a period of time to see if he can hypnotize someone into becoming an assassin and killing someone. He gives him a marksman mode that he goes into everytime he hears a certain ringtone and can trigger amnesia when the guy sees a blue and white polka dot pattern.
I had typed a long description out, but deleted it. If your interested in this sorta stuff,watch it, if not, no point wasting your time having to read a great big post
Pretty good watch though i thought.
My thoughts (if you've watched)
But near the end, at the theatre, They give the guy a "real gun" and tell him its loaded, but he's just to give it Derren after the show.
Perhaps when he got told to shoot Stephen, the guy was just playing along as surely you would think the gun must be fake?
He was supposed to be completely unaware that this was part of the show, but i think the gun could of been a bit of a giveaway.
Edit- They got this idea from conspicy theories, as apparently some people claim the Cia have done this to them. Such as the guy who shot US senator Kennedy. But this isnt the place for those discussions (i think?) so probably best not going there
