A detective explains how serial killer investigations actually work

Mark Williams-Thomas is a former police detective and a multi-award-winning investigative reporter. He is well known for working on investigations, including the "Yorkshire Ripper" Peter Sutcliffe. Williams-Thomas speaks with Insider about special investigative techniques and common issues in the process. Williams-Thomas is the author of “Hunting Killers” and has starred in television programs and crime series looking at cold case murders and violent crimes, such as “The Investigator: A British Crime Story” on Netflix. He’s reported on crime stories including Jimmy Savile, Oscar Pistorius, and the disappearance of Madeleine McCann. Find out more: https://www.williams-thomas.co.uk “Hunting Killers”: https://www.williams-thomas.co.uk/hunting-killers/