Establishing Likelihood Ratios for Patterned Garment Comparisons From Seam Measurement Data

• NCJ Number: 246092
• Journal: Journal of Forensic Sciences Volume: 58 Issue: 3 Dated: May 2013 Pages: 631-644
• Author(s): D. B. Johnson, M.S.; Victor E. Perlin, Ph.D.; Mitchell M. Rohde, Ph.D.; Alice C. Thomas, M.S; Cuong Q. Luu, B.S.; Jennifer Chang, B.S.
• Date Published: May 2013
• Length: 14 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

It is often challenging to ascribe an objective measure of confidence for identifications based on surveillance imagery from a crime scene.

Abstract

It is often challenging to ascribe an objective measure of confidence for identifications based on surveillance imagery from a crime scene. The present work seeks to address this deficiency in the case of garment comparison evidence by developing a quantitative method for establishing a conservative lower bound on the likelihood ratio LR for identifications involving patterned garments. The method is based on statistical analysis of pattern offset measurements taken from a sample of garments of the same type manufacturer, style, and size as the seized evidence. The developed analysis framework was demonstrated on different types of garments over a range of modeled surveillance imaging scenarios with variable image quality; the lower bounds on the LRs ranged from approximately 10-1 to over 400-1. The statistical model was tested and validated through a large-scale empirical study involving both simulated and human observer-performed garment comparisons. Abstract published by arrangement with John Wiley & Sons.