One of Britain's' most dangerous serial killers has issued a chilling warning vowing to kill again if given the chance.
Robert Maudsley has been in solitary confinement in a glass cell since 1979 and is Britain's longest serving prisoner, having been caged for 47 years for the murder of four men in the 1970s.
He carried out his own wave of vigilante justice, even killing three of his victims while in prison.
