Season 1 - Episode 6 - The Story of Mary Bell "The Tyneside Killer"

Mary Flora Bell (born 26 May 1957) is an English woman who, as a
child aged 10–11 in 1968, strangled to death two young boys in
Scotswood an inner-city suburb in the West End district of
Newcastle upon Tyne She was convicted in December 1968 of the
manslaughter of Martin Brown (aged 4) and Brian Howe (aged 3)