I’ve been face-to-face with dozens of sick serial killers but ’pure evil’ Brit terrified me most

HE’S come face-to-face with some of the most notorious serial killers in the world but one woman left criminologist Christopher Berry-Dee chilled to the bone. The ex-commando reckons Joanna Dennehy - who killed three men and stabbed two others - is the “most dangerous” person he’s ever interviewed. Berry-Dee, a renowned expert in the psyche of murderers, has met with killers like Roadside Strangler Michael Ross who murdered eight girls and women and John Robinson, known as the Slavemaster, who took the lives of at least three women. Yet he was most disturbed by a meeting with Dehenny, 41, who killed three men including her landlord in a killing spree in March 2013. Berry-Dee said: “She’s the most dangerous person I’ve ever, ever, ever come in contact with. “She’s not actually a big person and the knife she used isn’t that big dagger she was pictured holding but a pocket knife measuring about five inches. “To walk up to someone in the street like she did and stab someo