
Examining some of the most dangerous and prolific murderers in the UK and worldwide.

Colin Ireland targets patrons of a gay pub in Earl's Court, London.

A look at the London serial killer Dennis Nilsen, who murdered at least 12 men before being caught.

Scottish serial killer Robert Black attacks four young girls between 1981 and 1986; he is sentenced to life imprisonment at HMP Maghaberry with a minimum sentence of 35 years and is linked to 13 other child murders.

Four vicious murders put Mark Hobson at the center of a nationwide manhunt. Criminologists and psychologists try to decode this enigma.