The case for “investigate all”: Assessing the cost-effectiveness of investigating no CODIS hit cases in a sexual assault kit initiative

An increasing number of US jurisdictions have begun to submit their previously untested sexual assault kits (SAKs) for DNA testing. However, best practices for what should happen after testing are not well established. Should all cases be investigated regardless of the testing outcome or only those that returned a DNA hit? We examine an early-adopter jurisdiction that has completed testing and investigating all 5165 previously never tested kits. We explore and compare the criminal justice outcomes and cost-effectiveness of investigating: all cases, those with CODIS hits, and those without CODIS hits. Findings indicate the SAK initiative produced a cost savings to the community: $26.48 million ($5127 p/kit) after the inclusion of tangible and intangible costs of future sexual assaults averted through convictions, of which $9.99 million ($1934 p/kit) was from also investigating no CODIS hit cases. When considering only the costs to law enforcement, investigating all cases cost $12,000 p/additional conviction. Findings also illustrate the cost-effectiveness of investigating no CODIS hits cases and support an “investigate all” approach. This study enhances our understanding of the economic value of what comes after testing kits and investigating cases and provides a framework for jurisdictions for prioritizing resources and maximizing outcomes from testing.