Who was the world's first serial killer?
The woman responsible for the first documented serial killings in history was the a Roman poisoner, Locusta, who earned a living from making and selling poison in the first century AD.
Locusta is believed to be responsible for at least eight murders, including Roman Emperor Claudius, who died in 54 AD after having been poisoned by fungi. The murder was ordered by the emperor’s wife, Agrippa the Younger, but neither she nor Locusta were punished for the crime. The next year, Locusta was sentenced to death for another poisoning murder, but she was pardoned by Nero in return for killing Claudius’ son Britannicus. 14 years later, Locusta was once again sentenced to death and executed.
The poison maker Locusta tested her fatal mixtures on slaves, before poisoning one of her victims.