Who is the biggest human killer?

History’s Deadliest Killers: Monsters Behind the Numbers

When we think of the deadliest humans in history, names often tied to war or tyranny come to mind. But on a more personal, horrifying scale, serial killers have left trails of devastation that haunt the collective memory. Among them, a few stand out not just for their brutality, but for the sheer number of lives they claimed.

Luis Garavito, a Colombian criminal, terrorized children across Colombia, Ecuador, and Venezuela in the 1990s. His confirmed victim count ranges from 194 to over 300, mostly young boys, making him one of the most prolific known serial killers in history. Arrested in 1999, Garavito later confessed in exchange for a reduced sentence—a move that sparked outrage but also helped uncover the horrifying scope of his crimes.

Even more chilling is the case of Mariam Soulakiotis, a Greek Orthodox nun who ran a religious monastery outside Athens. Accused of murdering over 500 people—mostly followers who fell under her influence—her crimes came to light in the 1980s. Victims reportedly died from starvation, neglect, or poison, all under the guise of spiritual discipline. Though the exact number remains debated, the scale of her alleged atrocities is staggering.

Then there’s Pedro López, dubbed the "Monster of the Andes," who confessed to murdering 300 young girls across Colombia, Peru, and Ecuador in the 1970s and '80s. Though released from prison in the 1990s and later disappeared, his confessions shocked criminologists worldwide.

And while not all cases involve such high numbers, they’re no less tragic—like Javed Iqbal of Pakistan, who confessed to the murder of 100 boys in a horrific spree of abuse and disposal. His case, though documented differently in global records, underscores how evil often hides in plain sight.

These individuals remind us that the true measure of evil isn’t always in scale alone—but in the silence that allows it to grow.