Series 3

The astounding case of a woman and her lover who plotted to kill her husband, framing it to look like suicide in his caravan in Cenarth. And its jail for a builder who leaves a trail of overcharged unhappy customers.

A couple and their baby vanish in winter, sparking a nationwide manhunt with a tragic ending. And police hunt a fugitive bragging about his travels online.

How serial killer Steve Wright was finally convicted of the murder of teenager Victoria Hall. And a dispute over a teddy turns deadly when 15-year-old Elianne Andam is stabbed in broad daylight.

How the smugglers of hundreds of migrants using Tripadvisor-style schemes were jailed. And police hone in on a gang who stole gear worth millions from farms across north Wales.

The extraordinary story of the capture of prison escapee Daniel Khalife. And how anti-terror police hunt a suspect plotting an attack in London's Hyde Park.

The extraordinary hunt for the Carmarthen farmer's wife who lived a secret life as the godmother of a crime gang. Plus, how officers dismantled a Cardiff gang dealing heroin.

Detectives must catch two cold-blooded killers: one who has spent years plotting revenge against his prison guard, and another who killed a veteran, leaving his body in an outbuilding.

How detectives in Dyfed-Powys caught a 67-year-old man embarking on a terrifying stalking campaign against two young women. And a man in Cardiff who exposed himself to children is jailed.

How officers tracked a dangerous criminal in Manchester who pointed a loaded gun. And a determined detective solves the cold case murder of Jennifer Kiely.

Police hunt a gang of kidnappers who demand £5,000 for a man’s life, while the victim’s friends concoct their own daring plan to free him. And investigators unmask an extremist in Newport recruiting for so-called Islamic State.