made more troubling discoveries about nate's line-up. >> stainthorpe, when he filed for discovery, theyve him some pictures. it was the line-up. when he showed it to me i said, i never saw that. i had always been asking, where is my line-up picture? >> i was surprised i got the photo because the photo was of the line-up with the police officer pulling up nathan's shirt to show a tattoo. >> detective david o'callahan, he's the one that raised my what was significant about it is that i had a el rukn tattoo on my arm. and all these guys in that line-up got long-sleeved shirts except me. they wanted whoever seeing the line-up to see my tattoo that had nothing to do with the case. nobody even said they saw a tattoo, so why are y'all just showing my arm to these people, whoever is over there? >> i was doing this for a prosecution, to show mr. fields' loyalty and affiliation with the almighty el rukns, his gang membership. so in case mr. fields came to court later and said, oh, i never, ever was a bad boy, i never was involved in gangs or anything. why would you have a tattoo such as that? >>