The 10 hardest serial killers of all time

Aileen Wuornos

This American lady took the lives of seven men over the span of two years in Florida. A prostitute by profession, Aileen claimed to have been the victim of several attempted rapes and assaults, which, according to her, led to the accidental killing of the men while acting in self-defense. She shot dead all the seven of whom some were discovered stripped down to nothing. She was executed with lethal injection in Florida.