Subscribe now for more! Broadcast on 27/10/16 Joanne Froggatt describes the shift in roles from playing a maid in Downton Abbey to a .<br>Actress Joanne Froggatt explores the painful past and nuanced character of real-life serial killer Mary Ann Cotton from Dark Angel, as seen on MASTERPIECE .<br>All rights go to ITV &amp; the people on the set this is for educational use only.<br>The real life story behind ITVs Dark Angel - not sure how accurate either are though. However if you want more analytical &amp; factual info checkout the .
