(MCT) — CHICAGO — Even before Cook County State’s Attorney Anita Alvarez formed her Conviction Integrity Unit one year ago to deal with potential wrongful convictions, the case of Daniel Taylor had presented prosecutors with a particularly thorny problem: how to resolve a case in which Taylor, plus seven other young men, confessed to a double murder though records show he was in a police lockup when the crime occurred.

Twenty years after his arrest, Taylor’s confession carries the day for prosecutors. Though much has been learned about why teenagers sometimes falsely confess — Taylor was 17 when arrested — prosecutors point to his long and detailed confession as the most powerful piece of evidence in the case.