The first image of Joanne Froggatt as Victorian poisoner Mary Ann Cotton has been unveiled – and she looks like one of the most unlikely serial killers we’ve ever seen.

The Downton Abbey star has signed up to appear in two-part ITV drama Dark Angel about the real life murderess.

Joanne Froggatt as Mary Ann Cotton in Dark Angel



Joanne Froggatt as Mary Ann Cotton in Dark Angel (ITV)

 

Dark Angel also stars Alun Armstrong, Jonas Armstrong, Laura Morgan, Sam Hoare (Life in Squares), Emma Fielding and Penny Layden (Call the Midwife).



Cotton is a poisoner whose methods leave no visible scars, allowing her tally of victims to mount unsuspected by a Victorian society unable to conceive of a woman capable of such terrible crimes. Travelling around the North East, she insinuates herself into unsuspecting families, marrying and creating new families of her own – before killing them, taking their money and moving on.



Cotton was hanged after being convicted of killing three of her husbands, though some historians estimate she may have had more than 20 victims.

Joanne, known for playing maid Anna Bates in Downton, has swapped her apron for a bonnet as part of her Victorian costume.

Filming on Dark Angel has just begun in North Yorkshire and County Durham.