In September, 1935, two tourists make a gruesome discovery on the banks of a Scottish stream. When the police arrive, they know immediately that there’s been a brutal murder. But catching the killer won’t be easy, as they have used meticulous, surgical-like precision to hide their victims’ identities and cover their tracks.

Iain takes a look at a case that came to be known as The Jigsaw Murders – and delves into the pioneering forensic techniques that helped bring the killer to justice.

Murder They Wrote with Laura Whitmore and Iain Stirling is available weekly on BBC Sounds. Subscribe now so you never miss an episode. Email us at lauraandiain@bbc.co.uk.

Details of help and support with domestic abuse are available at bbc.co.uk/actionline.

A warning that this episode contains some violent scenes and scenes that some listeners may find upsetting.