Mark Williams-Thomas is an investigative journalist, an author and former police detective.

True crime documentaries are everywhere, and you've probably seen Mark in many of them. He was the man responsible for investigating and exposing Jimmy Savile which then lead to an avalanche of other abusers being arrested. Today we get an insight into what it's like to be a real life Sherlock Holmes.

Expect to learn who are the most disturbing criminals that Mark Williams-Thomas has ever met, what the biggest difficulties were when investigating Jimmy Savile, how Jimmy Savile got away with abuse for so long, what it was like interviewing Oscar Pistorious, how accurate life in Line Of Duty actually is, what Mark thinks about Making A Murderer and much more...