Compared with the four previous victims, Mary's origins are obscure, most of what we know about her comes from Joe Barnett, her boyfriend of 18 months and much of it could be embellished.
Mary was born in Limerick, Ireland, raised in Wales, and came to London in 1884 as a prostitute after she was widowed around 1882.
Mary worked at first in a high-class West End brothel and was even invited by a wealthy client to France, but she disliked the experience and soon returned to London.
Somehow, Mary ended up on the grim streets of the East End. In 1888, she and Joe Barnett had landed at 13 Miller's Court, on Dorset Street. Mary regularly let her homeless friends spend the night, despite Joe's protests. By November, Joe had lost his job as a dock worker and rent was 3 weeks overdue; they separated after a spat, but reconciled just hours before she was murdered.
Mary was young and was said to be pretty, although no photo exists of her in life. She was five-foot-seven, tall and buxom with blue eyes and flowing hair, usually going without a hat. Strangely, we don't know her hair color and her aliases are difficult to decipher.
"Black Mary" could well refer to her temper; Mary was violent when drunk but was otherwise quiet.
Mary's last night saw her singing "A Violet From Mother's Grave" before going out and returning home with a client.
Her landlord and his assistant found her later that morning at 10:45 AM.
Her body lay hideously mutilated on her bed; she was nearly beheaded, her face hacked beyond recognition, her breasts removed, her thighs flayed to the bone, her abdomen opened from groin to sternum and emptied, the organs scattered around her.