Searching for First-Degree Familial Relationships in California's Offenders DNA Database: Validation of a Likelihood Ratio-Based Approach

• NCJ Number: 236681
• Journal: Forensic Science International: Genetics Volume: 5 Issue: 5 Dated: November 2011 Pages: 493-500
• Author(s): Steven P. Myers; Mark D. Timken; Matthew L. Piucci; Gary A. Sims; Michael A. Greenwald; James J. Weigand; Kenneth C. Konzak; Martin R. Buoncristiani
• Date Published: November 2011
• Length: 8 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: Ireland

Annotation

A validation study was performed to measure the effectiveness of using a likelihood ratio-based approach to search for possible first-degree familial relationships (full-sibling and parent-child) by comparing an evidence autosomal short tandem repeat (STR) profile to California's ~ 1,000,000-profile State DNA Index System (SDIS) database.

Abstract

Test searches used autosomal STR and Y-STR profiles generated for 100 artificial test families. When the test sample and the first-degree relative in the database were characterized at the 15 Identifiler (Applied Biosystems), Foster City, CA) STR loci, the search procedure included 96 percent of the fathers and 72 percent of the full-siblings. When the relative profile was limited to the 13 Combined DNA Index System (CODIS) core loci, the search procedure included 93 percent of the fathers and 61 percent of the full-siblings. These results, combined with those of functional tests using three real families, support the effectiveness of this tool. Based upon these results, the validated approach was implemented as a key, pragmatic and demonstrably practical component of the California Department of Justice's Familial Search Program. An investigative lead created through this process recently led to an arrest in the Los Angeles Grim Sleeper serial murders. (Published Abstract)