Upcoming episodes, programme details and where to watch over the next seven days. All times are UK time.
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 boasting about his international travels.
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 a Caerphilly duo who smuggled hundreds of migrants into the UK via a Tripadvisor-style service were jailed. And police catch a gang causing misery for farmers across north Wales.
The extraordinary story of the audacious escape of 21-year-old prisoner Daniel Khalife. And how antiterror police hunted a suspect plotting an attack in London's Hyde Park.