Outcomes of DNA "Cold Hits": Social Science Research in Forensic Science, United States, 2000-2013 (ICPSR 36518)
Version Date: Aug 16, 2021 View help for published
Principal Investigator(s): View help for Principal Investigator(s)
Kelly Walsh, Urban Institute;
Dave McClure, Urban Institute
https://doi.org/10.3886/ICPSR36518.v1
Version V1
Summary View help for Summary
Through case studies in two sites, this project provides an in-depth view of the relationship between cases, DNA database hits and persons that contribute to those hits generated from two specific laboratories during two specific periods of time. It explores how well the primary Combined DNA Index System (CODIS) database metric, the hit, may correspond to case-level criminal justice system outcomes and examines how an uploaded profile is an investment in both short-term and long-term investigative leads.
A two-pronged approach was designed to address these issues. First, laboratory processing and CODIS datasets was analyzed according to traditional metrics used to track CODIS utility, such as upload and hit rate per case, per profile and for different offenses and evidence types. Next, a survival analysis was conducted to describe how uploading specimens to CODIS creates hits both in the short-term (at or near the time of upload) and in the long-term.
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Geographic Coverage View help for Geographic Coverage
Smallest Geographic Unit View help for Smallest Geographic Unit
None
Restrictions View help for Restrictions
Access to these data is restricted. Users interested in obtaining these data must complete a Restricted Data Use Agreement, specify the reasons for the request, and obtain IRB approval or notice of exemption for their research.
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Study Purpose View help for Study Purpose
The goal of this project is to provide an in-depth view of the relationship between cases, hits and persons that contribute to those hits generated from two specific laboratories during two specific periods of time. It also explores how well one of the primary Combined DNA Index System (CODIS) database metrics, the hit, may correspond to case-level criminal justice system outcomes and examines how an uploaded profile is an investment in both short-term and long-term investigative leads.
Sample View help for Sample
In Site A, there were 2,264 cases with at least one forensic profile uploaded to Combined DNA Index System (CODIS). Of these cases, 1,279 of them were connected to at least one known person or crime scene through a database hit. This demonstrates a 56 percent conversion rate between cases with uploads to hits.
When viewed on the specimen-level, these 2,264 cases produced 2,676 CODIS eligible forensic profiles that were uploaded to the database. Of these profiles, 1,534 of them were connected to other profiles through a database hit. This demonstrates a 57 percent conversion rate between profiles uploaded and profiles involved in a hit.
In Site B, there were 8,910 cases with at least specimen analyzed by the laboratory. Of these cases, 2,456 of them were connected to at least one known person or crime scene through a database hit. This demonstrates a 28 percent conversion rate between cases with evidence analyzed to hits.
When viewed on the specimen-level, these 8,910 unique cases resulted in 40,503 specimens analyzed by the lab. Of these specimens, 2,718 of them were connected to other profiles through a database hit. This demonstrates a 7 percent conversion rate between specimens analyzed and profiles involved in a hit. The following tables describe these rates in greater detail.
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Description of Variables View help for Description of Variables
The variables include criminal offenses and specimen matches.
Response Rates View help for Response Rates
Not applicable
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