A judge weighs whether to spare Missouri man from execution after evidence was mishandled

An evidentiary hearing in Missouri will determine the fate of a man on death row who thought DNA evidence uncovered in his case was enough to save him. A decades-old mistake by a prosecutors office has kept Marcellus Williams' life hanging in the balance. The 55-year-old is scheduled to be executed on Sept. 24 for the 1998 stabbing death of Lisha Gayle in suburban St. Louis. A judge on Wednesday presided over a hearing challenging Williams’ guilt. But the key piece of evidence to support Williams is DNA testing that's no longer viable. That's because testing revealed the murder weapon was mishandled by the St. Louis County prosecutor’s office more than two decades ago.