>> joe supposedly grabs the knife and goes after anthony in the creek bed, stabbing him. and yet there were no tire tracks or anything on the side of the creek. and so i thought, whoa, something's not right here. >> neil believed espinoza had to be lying. but a witness who was lying did not necessarily mean joe was telling the truth. neil needed to know more about joe's background. >> joe's father died when he was 17 years old. joe is the only boy in the family. so his father's death was very traumatic for him. >> i had to become the breadwinner. and as soon as i graduated i went right into the military. i was what they call a shade tree mechanic. i worked on everything from a jeep all the way up to a 35,000 kw generator that used to launch missiles.