He’s the UK’s number-one true crime author who made his name from his conversations with serial killers.

But what made former Royal Marine Christopher Berry-Dee want to get up close and personal with the world’s most depraved.?

From Aileen Wournos to the 'Monster of the Rivers' Arthur Shawcross, he has delved deep into the crimes and minds of psychopaths.

In an interview with Crime World, Berry-Dee explains what drew him to the dark world of more than 30 serial killers and why their shocking stories continue to fascinate the public.

Crime World, with Nicola Tallant, is a weekly Iri…

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