arrived to find a millionaire entrepreneur dead on his own kitchen floor. his name was bill mclaughlin, 55 years old, deeply religions and a true believer in the american dream, who made his come true. kind of a self-made guy, right? >> absolutely, yes. >> reporter: bill, said his daughter jenny, was the first in his family to go to college, first to found a company, first to end up with millions. not someone you'd think would wind up murdered. but here he was. >> you could tell there was not a physical struggle. there weren't things that were knocked off counters or things like that. >> reporter: you could tell, said voth, bill mclaughlin saw it coming, saw his killer. >> one of his movements was to put his hand up and try to block a shot. he got shot through the underside of a finger. so he saw his attacker. >> reporter: now voth needed to figure out, who was that last person bill mclaughlin saw? >> you're trying to take everything in, and you're trying