Clifford Danner is one of Mike Ross's friends, who was as a student wrongfully imprisoned for a murder he did not commit. He was found guilty because D.A. Cameron Dennis buried evidence that, if disclosed, would may have made him innocent.
He was sentenced to 16 years in jail, however after serving only 12 years he gets released after Harvey Specter proved his innocence and exonerated him. After that he was seen in Season 3 Episode 8 "Endgame" working in a restaurant (possibly waiter and bartender).