Mark Williams-Thomas: 'Everyone is capable of killing'

He’s the former police detective turned multi-award-winning investigative journalist who has been at the centre of some of the most high-profile investigations of recent years.

And as Mark Williams-Thomas documents his experiences in a tell-all book, he opens up about a life dedicated to justice - plus, reveals all about his jail visits to see Oscar Pistorius, and his pivotal role in Tia Sharp’s murder case.