Twenty years ago, Michael Stone was convicted of one of the most notorious crimes in Britain - the brutal murders of Lin and Megan Russell and the attempted murder of Josie. BBC Wales investigates new evidence suggesting that serial killer Levi Bellfield could be responsible.

The programme goes on the trail of the human traffickers who treat their victims like slaves and force them into a life of misery working.

As street gangs move into Wales, the programme speaks to those involved and follows the police as they tackle a growing threat.

Wyre Davies investigates the secretive world of illegal hunting and uncovers a network of badger baiters and their culture. The blood sport has been illegal for decades, so why is it still going strong?

To mark 70 years of the NHS, BBC Wales looks at the pressures facing the health service and meets people in the heart of the town that helped inspire Nye Bevan's vision of the NHS. Wyre Davies speaks to patients and staff and asks what needs to happen if the NHS is to survive to reach its centenary.

A man from Cardiff was at the centre of a terrorism network which sent money to Isis supporters across the globe. Wyre Davies travels thousands of miles following the money trail and discovers it may have funded a number of terrorist atrocities. And in Wales, we find a businessman accused by the FBI of being part of that network.

As the government's controversial new benefit Universal Credit is rolled out, Wales Investigates follows families struggling with their claims, and films behind closed doors with one council as it deals with mounting arrears and tenants in crisis.

BBC Wales Investigates the story of undercover policing - officers paid to spy on political activists. But some overstepped the mark - having relationships with women, sleeping with women and even fathering children with them. Two Welsh women tell their full story on TV for the first time about the impact it's had on them, and how they hope those responsible will one day be held to account.

The “Fred and Rose West of Barry” abused teenage girls for decades in the seaside town but did they act alone? The victims, who have waived their right to anonymity, believe there was a network of other predators, including police officers. Why was evidence destroyed and why was the couple the only abusers in the dock?

Over five months, Wyre Davies follows the lives of those living on the streets of Cardiff and questions why, despite efforts to help, so many continue to be trapped on those streets. Could a new solution, yet to be introduced, end rough sleeping?

The tragic death of Emiliano Sala in a plane crash touched thousands of people across the world. BBC Wales Investigates examines the circumstances of the crash and travels to Argentina to speak exclusively with his family and friends to find out more about the footballer and their hopes for justice.

With knife crime reaching record levels in Wales, Wyre Davies looks at the impact it is having on our streets. He speaks to a 15 year old who admits to carrying a knife for the last two years which, he says, he wouldn’t be afraid to use and goes on the front line with police trying to rid our communities of weapons. Can they succeed?

BBC Wales Investigates the people behind the multimillion-pound puppy industry. New owners can spend thousands of pounds on dogs, but what's really going on inside licenced premises? Wyre Davies confronts the breeders, inspectors and vets who should be policing the trade.