K.D. Kempamma is now considered one of India’s most loathsome serial killers and is arguably one of the nation’s very first woman serial killer. She earned the nickname Cyanide Mallika for her brutal and distinct method of claiming her victims.

Indian Tv
Cyanide Mallika first gained her victims’ trust, often by pretending to be some sort of leader endowed with a higher power. When she felt she had them ensnared, she would lure them into secluded areas and poison them, usually taking whatever possessions they had on them before running off. In total, six deaths were attributed to Cyanide Mallika.
28. Stacey Castor
The story of Stacey Castor is one so intricate and borderline outlandish, that you might swear it is the script to an obscure television drama. Alas, it very much happened, causing much confusion, grief, and pain for all involved. It is apt that Stacey Castor has been dubbed by many to be “America’s Black Widow.”

Syarcuse.com
It all started in 2000 when Stacey Castor’s first husband, Michael Wallace, died of poisoning. She soon remarried a man named David Castor, who died under similar circumstances in 2005. Additionally, Stacey Castor had a daughter named Ashley, whose father was the first man who fell victim to Stacey. She did not know the extent of her mother’s dark history, or of her father’s death, until a police officer reached out to her for questioning.