It seems as though they either ceased to exist or simply stopped being interesting after 9/11. When's the last time you heard of a Gein, a Dahmer or a Bundy? Where did they go? Are they now the "lone wolves" and terrorists we see plastered across the news? Are they too easily caught in the age of mass-surveillance, social media and smart devices? They've obviously appeared all over the globe for hundreds of years, but it seems as though there was a period in the latter half of the 20th century where a uniquely American cult of personality sprung up around them - prison marriages, fan mail, documentaries, high profile interviews - then vanished.