In 1884 two sisters were hanged at Liverpool's Kirkdale Gaol for murder and insurance fraud.
The crimes of Margaret Higgins and Katherine Flannagan so shocked the nation that they were immortalised in Madame Tussaud's Chamber of Horrors where they remained for nearly a hundred years.
But now new research claims that the two women weren't acting alone and were part of a much more sophisticated syndicate which killed at least ten people for their life insurance.
Angela Brabin joins Martha to tell her more about these gruesome murders that shocked Victorian England.
The BBC is not responsible for the content of external websites.