Celebrated criminologist and real life Cracker Professor David Wilson is a regular on This Morning, and now he's back with his own show, Killers Behind Bars on Channel 5.
The series looks into the intricacies of some of Britain's most notorious criminals and examines how and why they carried out their actions. David also looks for any unsolved murders that fit the killer's style, which they could also be responsible for.
Today he takes us into the mind of serial killer Stephen Griffiths, AKA the notorious Crossbow Cannibal, who killed at least three women in Bradford in 2010.