World's Most Evil Killers

After striking up a friendship in prison for previous murders, Stephen Unwin and William McFall's release had awful consequences.

Experts look back on the crimes of John Cannan as he moved in and out of prison.

Exploring a case highlighting the many dangers of online grooming; on 17 February 2014, fourteen-year-old Breck Bednar was lured to a London flat before being killed by a fellow teenager.

Thirty-two years later, a convicted killer serving life for manslaughter is found to be guilty of having committed a second murder.

A family's worst nightmare occurs when 16-year-old Becky Watts goes missing, and is found dead days later, murdered by her own stepbrother.

A fugitive from the United States murders one British police officer and tries to kill two more, sparking a nationwide search.

A master manipulator is accused of the murder of his wife, and is eventually caught out by a polygraph test - and his own fiancée.

Jailed for the dreadful murder of a children's author, Ian Stewart receives a second conviction for the death of his wife, six years earlier.

On the surface, Zahid Zaman portrayed himself as a pillar of the community, but the true story of this cult killer was deeply sinister.

A Texas serial killer, Anthony Allen Shore was matched to four murders after his arrest for a different crime.

A career criminal who was convicted of one murder and suspected of two others, Charles Albright was notorious for keeping eyes as trophies.

The notorious story of a man convicted of the murder of two young girls, as well as another killing at a military base.

The story of a killer who was infamous for his whimpering confessions over the phone after each of his murders.

Responsible for five murders, Joshua Wade avoided justice for years and later confessed to killings that started from when he was just fourteen.

A killer who goaded police and media during his spree, Heriberto Seda claimed to kill based on his victims' star signs.

A man who terrorized Phoenix in an extensive year-long crime spree, committing nine murders with no apparent motive.

The Alaska serial killer Robert Hansen who murdered at least seventeen women during a spree that lasted for more than a decade.

A killer who found some of his victims through ads, the case of Paul Runge became prominent in the debate over the death penalty in Illinois.

A serial killer and rapist who murdered at least 23 men and boys, this is the little-known case of Ronald Dominique.