Ian Woods reports on the drugs mix-up that halted Richard Glossip's execution, a Papal intervention into the case, and there is a big development in Glossip's private life.

Episode nine: The new search for witnesses

Sky News correspondent Ian Woods has been invited to witness the execution of a man in the US state of Oklahoma. Richard Glossip is on death row for a murder he says he didn't commit.  In this series, Woods examines the case, interviews the key people involved and discusses the controversy over the use of lethal injection.