Season 4 - Episode Guide

Peter Manuel was a Scottish serial killer who killed at least eight people between 1956 - 1958 around the Greater Glasgow area in Scotland. Manuel had prison for a string of sexual attacks but on his release it didn't take long for his psychopathic behaviour to escalate.

Dramatised account of 19th-century serial killer Mary Ann Cotton, aka the Black Widow, who travelled around north-east England and murdered men for their life insurance.

The case of Dr Ruxton, a physician who lived a quiet, respectable life in Lancaster, until in 1935 he beat, strangled and stabbed his wife and housemaid to death.

Examining the 1966 murders of three police officers in Shepherds Bush by Harry Roberts and two others. It led to a huge manhunt, and Roberts' release, 48 hours after being jailed.