March 8, 1863 - Mary Cowan

Mary A. Cowan (née Knight; March 8, 1863 – September 17, 1898), known as The Borgia of Maine, was an American serial killer who poisoned two husbands and four children between 1884 and 1894, and attempted to murder a third husband.

Content sourced from en.wikipedia.org/wiki/Mary Cowan under CC BY-SA 4.0.