Mary Ann Cotton was one of the most prolific poisoners in British history. Over the course of about 20 years she murdered between 16 and 20 people, all of them close to her, before she was found out and stopped. Show Notes: Sources and resources: The Elements of Murder by John Emsley Wikipedia https://www.britannica.com/biography/Mary-Ann-Cotton Mary Ann Cotton: Britain’s First Female Serial Killer by David Wilson “The baby born to Mary Ann Cotton in Durham Jail,” The Northern Echo, April 2018, https://www.thenorthernecho.co.uk/history/10068490.baby-born-mary-ann-cotton-durham-jail/ https://thecrimewire.com/true-crime/Mary-Ann-Cotton-Notorious-Victorian-Serial-Killer “Heavy metals: antimony, arsenic, bismuth, mercury by Reinsch test,” Forensic Toxicology Lab, Office of the Chief Medical Examiner, City of New York. https://www.nyc.gov/assets/ocme/downloads/pdf/MiscProcedures%20-%20H%20-%20Reinsch.pdf The Guardian, Letters, Mary Reid, Chessington, London, https://www.theguardian.com/society/2019/aug/18/misunderstanding-life-expectancy#:~:text=For%20example%2C%20in%201850%20in,life%20expectancy%20rose%20to%2057. Performance of “Mary Ann Cotton”, https://youtu.be/wiG3UdxSHS8?feature=shared Cover art photo: Mary Ann Cotton. Public domain.