Forensic psychiatrist Duncan Harding's job is to understand criminals.

His is a life spent with serial killers, psychopaths, violent children - in the prison service, the Old Bailey and at Broadmoor psychiatric hospital, he reckons daily with humankind's unimaginable capacity for cruelty.

Yet the humanity he discovers is perhaps the most shocking. The people Harding meets tell chilling stories of modern Britain, and the paths they were led down towards the most horrific of acts.

In his attempts to make sense of crimes, Harding confronts agonizing questions. When to call for justice, argue for mercy, break confidentiality - when to look closer, to believe, to forgive.

Broken Lives reveals the hard decisions we all must make when we come face to face with the unspeakable.