
An in-depth look at some of the world's most dangerous murderers.

Over a 25-year career of murder, Richard Biegenwald killed at least six people.

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

Arthur Shawcross, known as the 'Genesee River Killer,' was a serial killer who murdered eleven women from 1988 to 1990 in upstate New York.

A profile of Richard Roszkowski, the Connecticut triple-murderer who killed his ex-girlfriend, her nine-year-old daughter and another man in a brutal attack in 2006.