da jaime esparza. killer. >> i think there is enough believable and persuasive evidence in the case. >> reporter: nevertheless, he arranged a meeting. >> everybody thought it was crazy. they said, john he is the guy that convicted daniel. why would you go talk to him? >> reporter: good question. >> i'm like, he needs to know the truth. >> reporter: he marched into the da's office confident esparza would see the light, correct his mistake and free daniel. >> i told him daniel's confession was coerced. you have got the wrong guy. >> reporter: and? >> he tells me, "john, i can't do anything about it. you have to is neshnitiate it. get an appeals lawyer." >> reporter: he hired a lawyer. who said you have zero to slim chance of getting this kid off. >> reporter: what was it look to hear that? >> my heart sank. he's like, doesn't matter, john. the system doesn't care. it is about wing. and losing. >> reporter: the attorney told him there was really only one thing he could do. file a petition seeking a writ o

as does da jaime esparza, the da despite the court rulings and public sentiment remains convinced daniel is a killer and should be locked up for life. he is promised to try him all over again. >> let's have the jury deside whether or not -- decide whether or not he committed the crime or not. that's our policy. we do our talk in court. though the da declined our interview request until after he is planning to introduce new allegations one from a man who says he now remembers more than 20 years after the fact. hearing daniel confess, sometimes around his two trials. also allegations that daniel can be heard in a much dispultted phone call with his mother mumbling something that the prosecutor hears as i'm not innocent. and also, mumbella and daniel in prison telephone calls, conspired to influence witnesses when they can be heard stralt strategizing. a claim which according to mumbella amounts to a smear campaign by the da. are they trying to get at the truth? >> not at all. i believe they're just trying to hide the truth. >> reporter: does the da have a case? judge madrano has thrown out

soon there were demonstrations right outside da jaime esparza's window, demanding justice for daniel john mimbela. >> i figured the best thing i can do is just try to bring awareness that this is wrong. maybe we can change things. >> he believes in this cause with all his heart. and he's gone through great lengths to try to get other people to believe. >> reporter: and mimbela took up the cause like a marching band. >> full force. he spent a lot of money. hundreds of thousands of dollars. he has added a sense of credibility, of legitimacy. i think people started to pay attention. >> reporter: d.a. jaime esparza was paying attention, too. well aware of mimbela's street campaign and how it was helping shape public opinion. >> i think he's taken it, in some way, personally. because this was a case that was important to him. that this is an affront to justice. >> reporter: every time we come to the el paso courthouse and try to talk to d.a. jaime esparza, he has shut us down. no interview. no comment. has told us that he is ethically prevented from doing so. and so we've had to parse tog