Location: McWopetaz Metroplex, Illinois U. S. of A.
150 years ago - 1867 April 21 - The English woman who will become known as Mary Ann Cotton murders her stepson James Robinson, 6, with arsenic. He was one of about 21 the murderess dispatched over a 15 year period. The serial killer murdered several husbands, her children, additional stepchildren, a sister-in-law and a lover. Mary Ann went to the gallows in 1873.
This my opinion and to the best of my knowledge, that is, if I'm not joking.