but it's got some very, very powerful charges in it. >> for sam millsap, the letter was just another nvict claiming innocence. as the years went by, millsap began to have doubts. >> it never occurred to me when i was 35 years old that i was the smartest guy in the room, that the criminal justice system uld get it wrong in these cases. if i could do it over again, i never would have made the decision to prosecute ruben cantu for capital murder. mayer hawthorne playing ] blue moon is brewed with valencia orange peel, for a taste that shines brighter. (vo) treating others like we'd like to be treated has always been our guiding principle. ♪ ♪ohhhhhh, ou! guess what i just got? uh! ♪i used to be spellbound hello again. ♪i used to be spellbound hi. ♪i used to be spellbound that's a big phone. ♪in your arms. [screams] ah, my phone. ♪you built the flame ♪that warms my heart, ♪but lying and cheating ♪has torn us apart ♪and i'm moving on. pssst. what? i switched to geico and got more. more savings on car insurance? a-ha. and an award-winning mobile app. that is more. and an award-winning , the

. >> district attorney sam millsap, the youngest big city d.a.n the country, would now decide whether to try 17-year-old ruben cantu as an adult, making him eligible for the death penalty. >> we had very, very young people who were committing very adult crimes, very brutal crimes. and i was moved by that. the only thing that a prosecutor could do in that situation because of the brutality of the crime is to prosecute it as couple murder. and i had a perfect record in death penalty cases. >> ruben cantu's trial began on july 22nd, 1985. in court the prosecution's star witness, juan moreno, described how cantu shot pedro gomez in the head, then turned the rifle on him and riddled his body with bullets. >> mr. moreno was a very good witness. he was very sympathetic. at one time he was asked to raise his shirt and show the scars and the wounds that he had received. when the jury saw the scars, they made a pretty big impression. i also asked, are you able to identify in court today the man who shot and killed your friend? and he was able to say yes, i