This edition: The Scent of Darkness, Part 1 of 2
First aired: October 5, 2017.
Jane Tennison sent George Marlow down for six brutal murders. Now, two more women turn up dead with the same markings, doused in the same perfume. Is this a copycat killer or did Tennison get it wrong? How did the copycat get access to confidential information about Marlow's killings unless he was the killer all along?