the interrogation over, krebs brings investigators to the crime scene, keeping his promise to larry hobson he liked larry. it's a weird relationship, but it's a relationship. >> despite that relationship, hobson testifies at krebs' 2001 trial, persuading the jury to send the killer to death row for raping and killing the students. from san quentin, krebs writes christmas cards to hobson, grateful for the way the investigator questioned him with decency and kindness. >> it just shows that he respected me for the job i had to do. it's just business. >>> coming up -- what's it like to be 12 years old and sitting in the interrogation chair? >> i didn't do it! i didn't kill my sister. i wouldn't kill her. [ male announcer ] is zero worth nothing? ♪ imagine zero pollutants in our environment. or zero dependency on foreign oil. ♪ this is why we at nissan built a car inspired by zero. because zero is worth everything. the zero gas, 100% electric nissan leaf. innovation for the planet. innovation for all. innovation for the planet. a mouthwatering combination of ingredients...e for you! i know you'