University of Chicago engineering student and burglar, William Heirens, confessed to three murders including the gruesome killing of 6-year-old Northside Chicago girl 1946. Heirens claimed that police beat a confession out of him (not unheard of in Chicago). Police were under a great deal of pressure to find the killer and, after a number of publicly embarrassing missteps in the case, they arrested Heirens. Heirens is alive and imprisoned at the state correctional center in Dixon, Illinois.
I haven't a clue about Heiren's guilt or innocence, but as the Duke University case reminds us, prosecutors do make "mistakes" sometimes.