Transcript for Man in prison for 17 years set free after his lookalike is found
And we turn now to a fairly different type of redemption story. A man who maintained his innocence through almost 17 years in prison has finally been released. Thanks to his own detective work helping to track down his own look-alike. Turns out looks can be deceiving. Here's ABC's Alex Perez. Reporter: Finally free. After 17 years behind bars a man who says he was wrongfully convicted returning to lovingars arms. I hoped prayed every day for this day to come and when it finally got here it was an overwhelming feeling. Reporter: Richard Jones's nightmare over after tracking down another prisoner, his doppelganger, and the discovery kags doubt on H casting doubt on his guilty verdict. I believe it was a striking resemblance. It just blew me away. Reporter: Nearly 20 years ago Jones was charged with aggravated robbery in Kansas City, Kansas after being accused of trying to steal a purse in a parking lot. Jones had provided an alibi, and no physical evidence ever linked him to the crime. The case relied instead on eyewitness testimony. The victim told police the suspect was thin to medium build, tan with dark hair he pulled back, and out of a photo line-up of six mugshots Jones was identified. That eyewitness testimony landed him behind bars. But all along Jones adamantly maintained his innocence and tried to appeal his conviction. I couldn't let someone else's mistake make me waver in my faith and make me shy away from what was real and what the truth was and that was I was innocent and I knew it. Reporter: After 15 years of incarceration and declined motions, Richard Jones reached out to the university of Kansas school of law project for innocence and the midwest innocence project where law students took on his case and met with their client. During that visit Mr. Jones actually said to the students I keep getting mistaken for this guy named Ricky Amos. Reporter: Back at the office the students searched the Kansas department of corrections data base for Ricky Amos, and here's what they found. That's Jones on the right, Amos on the left. Both men with almost identical skin tone, facial hair, and cornrows. That was sort of a jumping off point to try to get Mr. Jones back into court to challenge his conviction. What would the victim and the other people that identified them say if shown these pictures. Reporter: But the discovery of this doppelganger came only at the end of a case founded on what many considered to be an imperfect law enforcement tool. Eyewitness identification testimony is always problematic because it's highly unreliable. Memories are not recorded playbacks like most of us think. Memories are recalled. It's a recollection, and there's a lot of inaccuracy that goes hand in hand with that. Reporter: And in fact -- About 72% of wrongful convictions come from mistaken eyewitness identifications. Reporter: The docket at the innocence project reflects the national statistics on wrongful convictions based on faulty eyewitness testimony. If I was going to survive I wanted to be able to bring the police a description of who had just raped me. Reporter: Jennifer kanino's detailed account of her rape led to the conviction of Ronald carton. In 1984 then 22-year-old kanino was attacked in her home. I thought I heard a noise in my bedroom and I said, who is that? Who's there? And then at that moment someone jumped up and jumped on top of me. I screamed, and then he muffled my scream with a gloved hand and put a knife to the side of my neck. Reporter: The assailant brutally raped her. She said that she kept her eyes open throughout the attack, trying to memorize every identifying feature. Maybe if he had an accent or a dialect that was different or if he had any unusual scars or tattoos or maybe he had lost a tooth or something that would be a feature that he couldn't alter later on. Reporter: Conton, who was also then 22 years old, was sentenced to life in prison. He never gave up his fight. And in 1995 with the help of new DNA technology he was exonerated. My spirit just like disintegrated. I felt so much shame and so much guilt for having been really a large part responsible. Not maliciously responsible but imperfectly responsible for a man losing 11 years of his life. And it didn't matter how many times I said I was sorry. It didn't matter what I did. I couldn't give him back those years. Jennifer Thompson and Ronald cotton's case is just a very powerful reminder of how not accurate our memories often are even when we want them to be. Their case just exemplifies a lot of the problems that happened in Mr. Jones's case across racial identification, a very bad police line-up. They are very closely linked in the issues that they raise. Reporter: Jones and Amos had never met until a hearing last Wednesday, when witnesses admitted they couldn't tell the two apart and the judge ordered Jones released. It made a lot of things understandable for me concerning this whole case because I just looked at how much me and this man looked alike and it was -- it was unbelievable. Reporter: Amos has denied any involvement with the crime he was never charged with or found guilty of the robbery. Though most anecdotes about doppelgangers may not usually involve crime and possible mistaken identity, the mysterious phenomenon in which two people look nearly identical is fairly common. Are you two twins? Reporter: Like Matty renslow and Patty eckhart. The pair are mistaken for twins but are complete strangers. No. You're kidding me. Reporter: Folklore has it that we each have seven look-alikes out there in the world. Dublin native Nia Gainey is working to prove that theory. She's already met three of her own doppelgangers. Oh, my god. Reporter: Since then Nia's become a doppelganger detective of sorts. These are all the filtered matches. Reporter: Co-founding the website twinstrangers.com to help others in their search. We have over a million people registered at the website, and we have thousands of matches. Reporter: As for Richard Jones the discovery of his doppelganger opened the door to his release. After nearly two decades Jones has just begun rebuilding his life. I'm definitely built for the challenge, just living my life starting over, and just doing it right this time. Reporter: For "Nightline" I'm
This transcript has been automatically generated and may not be 100% accurate.