murder, how does that affect you? >> my biggest fear is him buying into that, that he will most definitely follow into his father's footsteps. i don't want him to feel that he has no choices. you do have choices, and you make your life what you want it to be. you have that power. >> the power of choice. it's a message that zack carries with him everywhere he goes. and today is no different. in new york he's about to take his turn at shaping future global policy by speaking to an international audience. >> as an adult, i decided i was going to use what my father did as a means to bring attention to greater causes. i want people to realize that