The Interactions and Impacts of State DNA Database Laws

This project will investigate the effects of states' criminal offender DNA database laws (including the use of familial searches) on crime outcomes. In particular, the University of Virginia (UVA) will use longitudinal data on states' database policies and reported crime data from all U.S. states to test for positive and/or negative externalities of state database laws. This analysis will attempt to determine if expanding the reach of the database (by adding offenders directly or conducting familial searches) affect crime or clearance rates in neighboring states. UVA will also test for heterogeneous effects by the type of expansion, particularly which types of offenders are most cost-effective to include, from a national perspective, and if prevalence of positive externalities justifies federal funding to help build DNA database infrastructure.
This analysis is premised on the theory that as DNA databases expand, the probability of punishment increases leading to an increased incapacitation that would lead ultimately to a decrease in crime. Therefore although the cost to develop a DNA database infrastructure is expensive, adding additional classes of individuals to the database is relatively cheap and would exhibit a large return to scale, increasing its cost-effectiveness by increased incapacitation.
Thus this study will focus on three questions: 1. Does a DNA database expansion in one state help or hurt other states, in terms of crime rates and clearance rates? 2. How do these effects vary with distance from the expansion state? Are only border communities affected? 3. How do these effects vary with the type of expansion? How large are the externalities from adding convicted violent offenders, convicted property offenders, arrestees, or familial searches? To answer these questions, UVA will use UCR and NIBRS data on crime rates and clearances, as outcome measures. Information on states' database expansions and search policies will come directly from state statues. UVA will also incorporate data on the various state database sizes from SDIS labs, FBI statistics, and media reports. The effects of state policies on neighboring states will be analyzed with a difference-in-difference strategy and an instrumental variable strategy. Both strategies rest on the assumption that the timing of states' database expansions is exogenous to underlying crime trends. The first analysis will estimate outcomes as a function of a state's own DNA database laws and other states' laws, weighted by distance. The second analysis will examine differences in crime and clearance rates given the size of a state's database and the size of other states' databases, the timing of the state's database laws, pre-period crime rates and the size of the state's inmate population. ca/ncf