Robert Pickton preyed on vulnerable women from Vancouver's Downtown Eastside, many of them Indigenous. His case exposed devastating failures to protect them.

Dr. Marcel Petiot exploited the terror of Nazi-occupied Paris, murdering people who paid him to help them escape. He was convicted of 26 murders and guillotined.

Anatoly Onoprienko, 'The Terminator', murdered 52 people in Ukraine — often wiping out entire families in their homes. Inside one of Europe's deadliest sprees.

Andrei Chikatilo, the 'Rostov Ripper', murdered at least 52 women and children in the Soviet Union — and an innocent man was executed for one of his crimes.

Serhiy Tkach, a former police investigator, murdered at least 37 women and girls in Ukraine — and used his police skills to send innocent men to prison.

Moses Sithole, the 'ABC Killer', lured women with false job offers and murdered at least 38 in 1990s South Africa, earning a sentence of 2,410 years.

Pediatric nurse Genene Jones is suspected of killing dozens of infants in Texas. A cover-up nearly let her walk free — until prosecutors fought back.

Alexander Pichushkin, the 'Chessboard Killer', murdered dozens in a Moscow park, aiming to record a kill for every one of the 64 squares on a chessboard.

Coral Eugene Watts may be among the most prolific serial killers in US history — yet a controversial plea deal once nearly set him free. The full story.

Nurse Niels Högel was convicted of murdering 85 patients — and suspected of killing far more — by inducing cardiac arrests so he could 'play the hero'.

Hu Wanlin, the self-styled Chinese 'divine doctor', was linked to nearly 150 deaths through toxic herbal 'cures'. A disturbing case of lethal pseudo-medicine.

Carl Grossmann, the 'Butcher of Berlin', preyed on vulnerable women in 1920s Weimar Berlin. Inside the dark legend of one of the era's most notorious killers.

Louis van Schoor, the 'Apartheid Killer', shot dozens of mostly Black men as a security guard in 1980s East London. A case that exposed apartheid-era injustice.

Fernando Hernández Leyva, alias 'Pancho López', was convicted of 33 murders and confessed to over 100 — possibly Mexico's deadliest serial killer. His chilling case.

Nurse Orville Lynn Majors was convicted of murdering six patients with lethal injections — and suspected in dozens more deaths at a small Indiana hospital.

Juan Corona murdered 25 migrant farm workers in 1971 California, burying them in orchards near Yuba City — a case marked by overlooked, marginalised victims.

Fritz Haarmann, the 'Butcher of Hanover', murdered at least 24 young men in 1920s Germany. Inside one of the Weimar era's most notorious serial killer cases.

Belle Gunness lured suitors to her Indiana farm with marriage ads, then murdered them for their money. One of America's deadliest female killers — who then vanished.

Karl Denke, the 'Cannibal of Münsterberg', murdered at least 30 travellers over two decades in 1920s Germany — a respected churchman hiding monstrous secrets.

Mohammed Bijeh was convicted of abducting and murdering around 20 children near Tehran in 2004 — a case that exposed grave failures to protect vulnerable families.