Season 6

The murder of a 13-year-old Cornish schoolgirl on a school trip to France sparks an international hunt for the man responsible for a string of other sexual assaults in a myriad of locations.

21 years after she went missing, the body of a woman is found concealed in the depths of Coniston Water in the Lake District.

No overview available for this episode.

A series of coincidences lead to the unravelling of a string of deceptions by a conman and murderer.

No overview available for this episode.

Brian Blackwell was the son every parent dreams of having. Charming, confident and extremely clever: straight A grades at A-level meant he was about to embark on a medicine degree. But beneath all of the effortless success, was another story: Brian was gripped by a personality disorder, which made him obsessed with fantasies of power and brilliance. So when the 19-year-old student treated his girlfriend to a holiday of a lifetime in the US, with lobster, truffles and champagne, and a five-star hotel overlooking Central Park, suspicions began to be aroused. How had he found £30,000 to pay for the holiday? And where were his mother and father? The tragic story of how a seemingly "perfect" son took revenge on his parents when they discovered his spending habit was out of control. How he bludgeoned them to death one day; and calmly set off the next on a luxury trip to the States as if nothing had happened.

Mother and daughter dog breeders are stabbed to death in a remote cottage in the Norfolk Fens, sending shock-waves through a sleepy area not used to such brutal crime.

A young boy dies with a suspiciously large amount of salt in his system, and the question which must be answered is how it came to be there. Suspicion falls on his own mother.

A series of nail bomb attacks take place in crowded areas of London, but just as the police think they have identified the targets, the bomber changes tack.