Everyone in the US knows about Jeffrey Dahmer, Ted Bundy, and Aileen Wuornos. But serial killers exist beyond the US.

From the "Butcher of Rostov" to the "Little Old Lady Killer," these are nine of the most terrifying killers from around the world that Americans may never have heard of.

Editor's note: A warning some of these accounts feature graphic depictions of violence, sexual abuse, and murder.