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NCJ Number: 218823 Find in a Library
Title: Statistical and Population Genetics Issues Affecting the Evaluation of the Frequency of Occurrence of DNA Profiles Calculated From Pertinent Population Database(s)
Corporate Author: US Dept of Justice Federal Bureau of Investigation
Laboratory Branch
United States of America
Date Published: July 2000
Page Count: 9
Sponsoring Agency: US Dept of Justice Federal Bureau of Investigation
Quantico, VA 22135
Sale Source: US Dept of Justice Federal Bureau of Investigation
Laboratory Branch
2501 Investigation Parkway
Quantico, VA 22135
United States of America
Document: HTML
Type: Report (Technical)
Format: Document (Online)
Language: English
Country: United States of America
Annotation: The FBI Laboratory's DNA Advisory Board clarifies issues that arise for the following special cases: source attribution or identity, cases in which relatives may be involved, interpretation of DNA mixtures, and the significance of a match derived from a felon database search.
Abstract: Those who question the concept of assigning source attribution for DNA evidence often focus on the difficulty of establishing beyond doubt that a DNA profile is carried by only one individual in the entire world. This reasoning is illogical, however, since the parameters of a given case would rarely involve the entire world's population in the pool of suspects. The possibility of a close relative (typically a brother) of the accused being in the pool of potential contributors of crime scene evidence should be considered in case-specific context. The best action is to obtain a reference sample from the relative who had access to a crime scene. When a legitimate suspected relative cannot be typed, a probability statement can be provided. DNA samples derived from two or more contributors are sometimes encountered in forensic biological evidence. Interpretation of DNA mixtures requires careful consideration of factors that include, but are not limited to, detectable alleles; variation of band, peak, or dot intensity; and the number of alleles. As felon DNA databases develop in all 50 States, searches for matches between evidentiary and database profiles will become increasingly common. Two questions arise when a match is derived from a database search: "What is the rarity of the DNA profile?" and "What is the probability of finding such a DNA profile in the database searched?" This article addresses the latter question, which is especially important when a DNA profile found in a database search matches the DNA profile of an evidence sample. 11 references
Main Term(s): Police policies and procedures
Index Term(s): Crime laboratories; Crime laboratory management; DNA fingerprinting; Forensic sciences; Investigative techniques; Statistical analysis
Note: From Forensic Science Communications, V 2, N 3, July 2000; downloaded June 12, 2007.
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