Britain's Most Evil Killers - Season 4

Harold Shipman: A profile of one of the most prolific serial killers in history. With an estimated victim-count of 250, what drove his horrific crimes?

Robert Napper: Known to some as The Plumstead Ripper, he was convicted of two murders, but his victim count is actually estimated to be much higher.

A closer look at the murderer Stephen Seddon, a convicted fraudster who killed his parents in a cold-blooded crime as he tried to get his hands on their £230,000 estate.

A profile of serial killer Dale Cregan, who was sentenced to life in prison after the senseless murders of two men and two police officers in 2012.

The story of 21-year-old Anthony Arkwright from South Yorkshire, who in 1988 went on a killing spree in which he murdered three people - including his own grandfather.

A profile of the cold-blooded killer John Sweeney, nicknamed the Canal Killer due to the places he dumped the body parts of his victims.

A look at the crimes of Andrzej Kunowski, a man so vicious he was nicknamed the Beast after raping and murdering a 12-year-old girl in 1997.

The story of Hartlepool man Arthur Hutchinson, who achieved notoriety in 1984 when he broke into a Sheffield home and took the lives of three family members in a senseless killing.

Peter Moore, the killer dubbed 'The Man In Black', a murderer who took the lives of four innocent men for fun.

A profile of the double-killer who branded himself the 'Angel of Mercy', after murdering two of his neighbours in cold blood.