3x6 - Blue Murder

Fourteen years earlier, a fifteen-year-old girl named Alicia Turner was murdered, and a seventeen-year-old named Nick Randall was convicted of her murder. When Tommy Granato claims Randall is innocent, Barrow asks the team to take a look into the investigation because that was her first major case. The squad soon nabs a three-time loser named Al Snedden who points them to his former cellmate Wally Maestre, swearing that he confessed to the murder. When Snedden gives the squad information that only the killer could know, the squad turns all their eyes on Maestre, yet his sister Bonnie provides him with an iron-clad alibi.