Inca mummy boy long thought to have frozen to death was actually killed by a blow to the head

In 1954, the body of an eight-year-old boy was discovered at an elevation of 5,400 meters in the Chilean Andes. He had lain undisturbed in frozen ground for more than 500 years, his skin, hair and fingernails still intact.

Scholars at the time concluded that the child had died peacefully in the cold, as if falling asleep. Signs of frostbite on his fingers and the absence of any visible injuries made that the accepted explanation for the next 70 years.

Now, a research team that recently re-examined the 500-year-old body using computed tomography (CT) scanning has reached an entirely different conclusion.

A joint Chilean-Spanish research team published their findings in volume 12, issue 29 of the international journal Science Advances, concluding that the boy, long known as the "Child of Cerro El Plomo," did not freeze to death but died from a powerful blow to the head.

The ancient Inca Empire practiced a ritual known as "capacocha," in which selected children were brought to mountaintops as sacrificial offerings.

The Inca regarded high mountains, which they called "apu," as sacred beings. A chosen child was believed to enter the divine realm through death, becoming a bridge between the village and the gods.

The ritual began by gathering children in the capital, Cusco, then setting out toward the mountains on foot. Villages along the pilgrimage route offered food to the procession and shared meals with those passing through.

The research team analyzed the causes of death of three individuals: a nine-year-old girl and an 18-year-old woman found in 1976 at Cerro Esmeralda in Chile's northern Atacama Desert, and the eight-year-old boy discovered in 1954 at Cerro El Plomo. Radiocarbon dating placed all three deaths in the mid-15th century, around 1440 to 1480 AD.

The team drew their conclusions by analyzing the subjects' hair.

Hair grows roughly 1 centimeter per month, recording the chemical composition of food eaten and water consumed as it grows. By cutting strands from root to tip and analyzing them in sequence, researchers can reconstruct a timeline of what a person ate and where they were in the months before death.

Soil, water and crops vary in chemical composition from region to region, and dry, humid, high-altitude and low-altitude environments each leave distinct chemical signatures. A shift in the composition recorded in a strand of hair therefore indicates that the person had moved to a different location.

The analysis showed that all three individuals passed through multiple different environments in the months before their deaths. The nine-year-old girl was estimated to have traveled between 900 and 1,200 kilometers over roughly five months. The 18-year-old woman covered a similar distance in about three months. The eight-year-old boy walked approximately 2,600 to 2,800 kilometers from Cusco to a valley in central Chile over about nine months.

To determine the cause of death, the research team examined the boy's skin under a magnifying glass and studied his tissue samples under a microscope.

Contrary to earlier findings, there were no signs of freezing or cellular tissue damage — the traces that would be expected had the boy died of hypothermia were simply absent.

Instead, the researchers found a depression on his left forehead measuring 3.7 centimeters wide and 2 centimeters tall. A CT scan revealed a 3-centimeter fracture in the frontal bone beneath it. There were no signs of the bone beginning to heal, indicating that the boy died shortly after sustaining the injury.

The team created a three-dimensional reconstruction of the boy's skull and ran simulations applying impacts of varying force. A force of approximately 2,800 newtons — roughly equivalent to a full-strength blow delivered by a person — produced injuries most closely matching the actual wound.

The injury's location, near the temple, is one of the skull's most vulnerable areas. The researchers concluded that the wound was not the result of a fall but of a deliberate, targeted strike.

The team compared their findings with evidence from other capacocha sites. Skull fractures were found at Ampato and Pichu Pichu in Peru, while stab wounds were documented at Chuscha in Argentina.

The team was careful to note, however, that their analysis assessed physical plausibility rather than reconstructing exactly how events unfolded. Skin and clothing were not factored into the calculations. The researchers added that the available evidence does not allow them to determine who struck the blow or in what position.

DOI: 10.1126/sciadv.adz9055

Verónica Silva-Pinto et al., "Pilgrimage to sacrifice: Mechanisms, causes, and time of death of the Western Andean Capacocha of the Southern Tawantinsuyu." Sci. Adv. 12, eadz9055 (2026).