Capture-recapture to estimate criminal populations

Abstract

Methodology is presented that allows to estimate the size of population from a single register, such as a police register of offenders. A capture-recapture variable is constructed from Dutch police records and is a count of the police contacts for a violation. A population size estimate is derived assuming that each count is a realization of a Poisson distribution and that the Poisson parameters are related to covariates through the truncated Poisson regression model or variants of this model. As an example, estimates for perpetrators of domestic violence are presented. It is concluded that the methodology is useful, provided it is used with care.