Updated

A 76-year-old former security guard serving a life sentence in the 1957 slaying of a 7-year-old Illinois girl could go free soon after a prosecutor found fault with the investigation and new evidence corroborated an alibi.

One of the oldest cases in the U.S. ever to go to trial will be back before a DeKalb County court Tuesday, not far from Sycamore, where Maria Ridulph was abducted, stabbed and choked to death. Jack McCullough was convicted in 2012, some 55 years after the death.

DeKalb County State's Attorney Richard Schmack said in a scathing filing last week that a review turned up serious missteps during the investigation and prosecution. He also said there was new evidence supporting a McCullough alibi.