Study: More than half of police killings are undercounted

The study, conducted by researchers at the University of Washington and published on Thursday in The Lancet, a major British medical journal, amounts to one of the most comprehensive looks at the scope of police violence in America, and the disproportionate impact on Black people.

Researchers compared information from a federal database known as the National Vital Statistics System, which collects death certificates, with recent data from three organizations that track police killings through news reports and public records requests. When extrapolating and modeling that data back decades, they identified a startling discrepancy: About 55 percent of fatal encounters with the police between 1980 and 2018 were listed as another cause of death.

The findings reflect both the contentious role of medical examiners and coroners in obscuring the real extent of police violence, and the lack of centralized national data on an issue that has caused enormous upheaval. Private nonprofits and journalists have filled the gap by mining news reports and social media.