Abstract: Political violence unleashed by the Communist Party of Kampuchea regime (1975-79) to transform the economic and environmental landscape of Cambodia resulted in up to 3 million deaths, i.e. between 20-25% of the population. How does this historical genocide influence contemporary household welfare? Satellite images of Khmer Rouge’s failed agricultural projects provide a source of exogenous variation in mass killing sites. Additionally, spatial power relations across military-administrative regions are exploited as a border discontinuity. My instrumental variable and regression discontinuity analyses find persistent impacts on contemporary household wealth and village-level poverty, driven by lower human capital, limited structural transformation and lack of public goods and services. Zero-first-stage tests, plausibly exogenous instruments and causal machine learning methods establish the validity of the proposed research designs. This paper contributes new evidence on the economic legacies of large-scale human capital destruction.