Mary Ann Cotton’s kill count is somewhat dubious. What is known, however, is that she killed multiple husbands and many of her own children. She was also very sly about how she went about her dirty business, although the pain her victims faced was far from subtle. All the victims were related to Cotton in some way.

Thinglink
Cotton had several husbands over the course of her life, four total. Of those four, she was convicted of killing three of them. She is also said to be responsible for the deaths of a dozen of her own children. Cotton was tried in court after she being accused of poisoning her stepson with arsenic. She was hanged for her crimes.
14. Johanna Altvater
Johanna Altvater, one of Hitler’s Furies, was just 22 when she committed her crimes. Sickeningly, she preyed on Jewish children. She would gain their trust by offering them candy. Once they took it and started eating it, she shot them in the mouths. But that was not the full extent of her crimes.

Mamamia
Once, she went to a hospital filled with Jewish children. After observing the kids, she chose one to toss three floors out the window onto the cement ground below. That child was not the only victim, sadly. In another case, Altvater lured in a toddler, picked him up, then proceeded to smash his head into a ghetto wall until he died. The child’s father was forced to witness the murder. Several others sustained severe injuries. After the war, she stood trial but was acquited due to lack of evidence.