Why do serial killers kill? Is it an innate thirst for blood that starts from a very young age? Or is it something that a pained and abusive childhood forces a person to become? Everyone has their own opinion on the matter, but these two case studies will make you think about what you thought you knew and that, in reality, it might not be a case of nature or nurture, but instead a case of both. Hannah Briant is a student at Francis Holland Sloane Square who plans to study criminology in university to explore discussions like this in a deeper way. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at https://www.ted.com/tedx