Capture-Recapture for Hidden Crime Populations

Capture-recapture, known in criminology and public health as multiple systems estimation, infers the size of a hidden population — undocumented homicide victims, trafficking victims, problem drug users, undetected offenders — that no single source counts completely. By examining how much two or more incomplete lists overlap, it estimates how many cases were missed by all of them: the 'dark figure' of crime. Borrowed from wildlife ecology, the method was synthesized for human populations by the International Working Group in 1995 and brought to criminal-justice policy by Bird and King.