25 years after he first reported on it, Sir Trevor re-visits the case of Beverley Allitt, one of Britain's most prolific serial killers.

It is estimated that about 1 in 100 people are psychopaths, but although many violent offenders fall into this category it does not mean all psychopaths will be violent. Nor does it mean all violent people are psychopaths. Is the tendency towards psychopathic behaviour something that people are born with, or is it something caused by our upbringing? Find out about the indicative behaviours doctors look out for when making a diagnosis of psychopathy.

In this powerful new documentary, criminologist Dr Graham Hill, a former senior Met detective who was in Portugal during the early stages of the investigation assisting local police, returns to Praia da Luz for the first time. Revisiting the scene of her disappearance, unpicking Brueckner’s criminal history in both Portugal and Germany and meeting those who knew him to build a detailed offender profile, Dr Hill examines the case against the man who remains the prime suspect- and who has consistently denied any involvement in Madeleine McCann’s disappearance.