Two of the 1800's worst.
Serial killer poisoners Mary Ann Cotton and Thomas Neill Cream.
Mary Ann Cotton, The First Serial Killer In British History (allthatsinteresting.com)
Mary Ann Cotton – Bio, Personal Life, Family & Cause Of Death - CelebsAges
Thomas Neill Cream - Wikipedia
Thomas Neill Cream: The Serial Killer Doctor Of The Victorian Era (allthatsinteresting.com)
The Evil Deeds of Dr. Cream - Canada's History (canadashistory.ca)
