Gruesome instances of mass killing have punctuated the 6000 year-long sequence of the prehistoric South American Andes, an area that encompasses modern-day Ecuador, Peru, Bolivia, and northern Argentina and Chile. Accurately gauging the intensity and intent of violence—in particular mass extermination—among people who left no form of written language, requires a forensic skeletal approach that informs on both the cause and manner of death, as well as the nature of corpse disposal or burial, which itself reveals how bodies were treated after death.

Time and again, aggressors in the Andes marshalled common tactics, including the sacking of towns and sanctuaries, instituting systems of mass displacement, controlling reproduction among women, moving children from subservient groups, and orchestrating the maiming and murder of both formidable rivals and civilian noncombatants alike. These violent episodes of eradication may best be understood as outbreaks of local communal strife, limited in both place and time. These genocidal moments capture the collective murder of targeted sub-population groups. The physical and material record helps us identify catastrophic death assemblages, reconstruct the profiles of victim and perpetrators, discern the methods of murder, and even deduce underlying motivations for attack.