A State Census of Unsubmitted Sexual Assault Kits: Comparing Forensic DNA Testing Outcomes by Geographic and Population Density Characteristics*

Abstract

A growing number of U.S. cities and states have large numbers of unsubmitted sexual assault kits (SAKs) in police property facilities. Prior research conducted in large urban cities has found that testing these kits yields a sizable number of DNA profiles that meet FBI eligibility for upload to the national criminal DNA database CODIS (Combined DNA Index System) and uploaded profiles return a substantial number of matches to existing criminal profiles in CODIS. It is unknown whether these findings are unique to large urban cities with high crime rates. The purpose of current study was to document forensic testing outcomes from a state census of previously unsubmitted SAKs, which included large urban-suburban centers, as well as smaller cities and rural counties. We inventoried all previously unsubmitted SAKs in Michigan (N = 3422 SAKs) and submitted all kits for forensic DNA testing. A total of n = 1239 SAKs had a DNA profile that met eligibility for upload into CODIS (36.2% unconditional, 56.5% conditional CODIS eligible rate) and n = 585 SAKs yielded a CODIS Hit (17.1% unconditional, 47.2% conditional CODIS hit rate). These rates are consistent with studies from urban areas suggesting approximately half of SAKs tested yield a CODIS profile and approximately half of those uploaded profiles yield a hit. We compared SAK forensic testing outcomes by geographic and population density characteristics, and although rates were often higher in larger metropolitan areas, the obtained rates in micropolitan and rural areas suggest testing is warranted in smaller jurisdictions as well.

Recent advances in forensic biology and forensic DNA typing: INTERPOL review 2019–2022

“…A number of articles have been published in the past three years describing success rates with examining SAKs and the policies surrounding them. For example, an evaluation of 3422 unsubmitted SAKs in Michigan found 1239 that produced a DNA profile eligible for upload into CODIS with 585 yielding a CODIS hit [ 128 ]. In addition, results from a groping and sexual assault case were presented to support the expansion of touch DNA evidence in these types of cases [ 129 ].…”

A window of opportunity: Examining the potential impact of mandatory sexual assault kit (SAK) testing legislation on crime prevention.

“…As part of that work, Cleveland tested a nonrandom sample of 4,966 SAKs, which produced higher yields: 59% of tested kits generated a CODIS-eligible profile, and 66% of uploaded profiles returned a CODIS hit (Lovell et al, 2018). To document SAK forensic outcomes from nonurban communities, Campbell, Javorka, et al (2020) tested a state-wide census of 3,422 previously unsubmitted SAKs, which included kits from small cities and rural counties. Over one-third of kits (36%) produced a CODIS eligible profile, and 47% of the uploaded profiles returned a CODIS hit.…”

“…In this project, we tracked a sample of 7,287 previously unsubmitted SAKs collected in Detroit, MI that were outsourced for forensic DNA testing (Campbell, Javorka, et al, 2020). We documented how many offender CODIS hits were generated, and then we obtained each identified offender's adult Michigan criminal history records and segmented their records to examine incidents committed before, during, and after their SAK testing window.…”

“…To date, most research on untested SAKs has been conducted in large, urban cities with high crime rates, and though Detroit is unique even within that reference group, our results were nevertheless strikingly similar to projects conducted in communities with more racial/ethnic and economic diversity (Lovell et al, 2018(Lovell et al, , 2020Strom et al, 2018;Whisman & Roberts, 2017). Emerging research on untested SAKs in small urban and rural communities has documented similar CODIS hit rates (Campbell, Javorka, et al, 2020), but why there is such convergence across such disparate communities is unclear and merits further research. CODIS hit rates are dependent on CODIS uploads (both forensic samples and known references samples), and the extent to which there are consistent practices-or consistent biases-to ensure that certain offenders provide police with DNA samples may explain why CODIS hit rates are similar across different community contexts.…”

The Return on Investment from Rapid DNA Testing of Sexual Assault Kits

“…In the United States, the backlog problem for DNA analysis is exacerbated by the revelation that many jurisdictions had warehoused SAKs, failing to send them to the crime laboratory for analysis. [12][13][14][15][16] Recent estimates suggest that even with efforts of the last several years to discover and test these warehoused SAKs, some 300,000 to 400,000 untested SAKs remain. 17 The U.S. problem is widespread and includes the state of Kentucky.…”