The Mystery on Johnsburg Road

20/20 goes to the village of Johnsburg, Illinois, in order to investigate the December 2002 disappearance of Brian Carrick. He went in to his job at a grocery store and never returned. A co-worker Mario Casciaro is eventually arrested and convicted of murder despite the lack of a body, a weapon, or DNA evidence. In an exclusive prison interview, Casciaro claims that he is innocent of the crime.