Lamar Johnson was 21 in 1995 when he was charged with the murder of a friend, Markus Boyd. Johnson said he was miles away with his girlfriend and daughter, but he was convicted and sentenced to life in prison primarily based on the testimony of Greg Elking, who picked Johnson out of a police lineup. Nearly three decades later, Johnson's conviction was vacated after Elking recanted his identification of Johnson. Now, Johnson tells the story of his fight to prove his innocence.