First Western serial killer ...

[Baruch]

https://www.youtube.com/watch?v=SY4i_ONbZyE

Locusta was from Gaul, but reached fame in Rome.  Murder Incorporated ... but also the killing of children and probably an inducer of miscarriages.  She wasn't the first great poisoner however, that title goes to King Mithridates VI of Pontus (in N Anatolia).  He took his own poisons in small doses to build up immunity against attempts at assassination.  He was so immune, that when he tried to commit suicide by poisoning, to escape the vengeance of the Romans (who had been victimized by the first ethnic cleansing/mass murder in Anatolian history) he was immune.  He had to have a slave kill him with a sword.  People like Locusta were why pharmacology was suspect for millennia, and part of the reason why abortion was a criminal act, and women were suspect (they had mastered plants since the Stone Age).  Modern legal pharmacology only came about when modern male pharmacology came about in the early modern period with Paracelsus.  Of course men would never engage is suspicious activity, right?