Although the United States is known to have the highest number of serial killers compared to any other country, some of the most heinous murderers in history have emerged from the Southern Hemisphere. These individuals have left behind a trail of hundreds of victims, including children, women, and men, earning them chilling monikers such as "monster," "beast," and "sadist" as society struggled to comprehend their abhorrent actions. A number of these killers specifically targeted impoverished, indigenous women and children living on the fringes of society, with law enforcement exacerbating the dire situation by inadequately investigating the victims' deaths. While the public expressed outrage over these horrific crimes, many judicial systems in the region were ill-equipped to address such brutal offenses, often imposing maximum sentences that failed to reflect the severity of the crimes—such as a child murderer who was released after merely 14 years. This discussion highlights eight of the most fearsome serial killers from South America.