german, a former fbi agent, and thinking like isis the life of an undercover agent, and also michael mcfadden, and also mu p bin shaikh and michael, first to you, we were worried about three men from brooklyn and today, jihadi john and you work with terror cell and what makes this them tick? >> each story is individual. there sis a lot of different things that push and pull somebody into engaging into this type of e behavior. one of the things to consider as well is that these are not necessarily the same type of behavior. what would drive somebody to join isil and to be involve mdd in the horrendous murdrs might be different p from somebody who might want to go the syria to fight against the assad government. government. >> and it is not the same psychological profile. >> right. and not the same behavior. and somebody who might want to fight against the assad government, and p you fight against certain groups you will get the u.s. money and resources. so what might pull somebody there might be different from what somebody would want to do to actually engageing in the terrorist acts. >> and s