. >> in 2002 at 18, sam herr was charged in the murder of another teenager. in dad knew in hindsight, it did not look good. that didn't buy you a lot of rhythm from law enforcement? >> no. i understood that. it was imperative to start looking immediately. >> he wanted to find is son to prove he was innocent. the orange county prosecutor also wanted to find sam quickly for entirely different reasons. >> he has a dead woman in his apartment and he's missing. you factor in afghanistan and he was a trained killer. he's been accused of this before and this guy could be potentially dangerous. >> the detectives and the data hunted sam independently. but on parallel tracks. detective spoke with sam in neighbors. >> i saw sam that day and had a short conversation with sam. >> rachel and dan said he was with another man they did not know. a man in a black hat. it seemed a potential lead. meanwhile, steve them there were recent transactions on the bank account he and sam shared. the trio led to long beach where sam's atm card was used to order a pizza. cops staked out t