Forty years ago police revealed a drugs ring had been producing and distributing LSD from rural West Wales to the rest of the world. 'Operation Julie' was one of the UK's most successful undercover police investigations. Mali Harries explores the evidence from the case and the effects the undercover operation had on the detectives involved.

This week Mali Harries follows in the footsteps of a North Wales Police investigation to catch a killer who did everything he could to lead the police astray.

Forty years ago police revealed a drugs ring had been producing and distributing LSD from rural West Wales to the rest of the world. 'Operation Julie' was one of the UK's most successful undercover police investigations. Mali Harries explores the evidence from the case and the effects the undercover operation had on the detectives involved.

A man from Caernarfon has been given a 50 year sentence in an American prison after raping a 10 year old girl in Oregon. But how was he caught? Mali Harries travels to Oregon to meet the detectives who arrested Gareth Hall.

The case of a missing landlord in Swansea was a complete mystery for detectives in South Wales. They feared the man had been murdered but with no body it was a challenge to prove the case. In the first of the new series, Mali Harries reveals the evidence from the investigation and retraces the steps of the Welshman who hid a body in a quarry before going on the run.