Cadaver Dogs--A Study on Detection of Contaminated Carpet Squares

• NCJ Number: 221729
• Journal: Forensic Science International Volume: 174 Issue: 1 Dated: January 2008 Pages: 35-39
• Author(s): L. Oesterhelweg; S. Krober; K. Rottmann; J. Willhoft; C. Braun; N. Thies; K. Puschel; J. Silkenath; A. Gehl
• Date Published: January 2008
• Length: 5 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

This investigation tested the comparative evaluation of the reliability, accuracy, and specificity of three cadaver dogs in the detection of scents during the early postmortem interval.

Abstract

Results indicate that the well-trained cadaver dog is an outstanding tool for crime scene investigation displaying excellent sensitivity, specificity, and having a positive predictive value, as well as accuracy. A total of 354 searches were performed, and each search involved a design construct of six possible choices of contaminated or uncontaminated carpet squares. Results indicated that the dog’s sensitivity for the detection of contaminated carpet squares was 98 percent for those squares contaminated for a maximum of 10 minutes and 86 percent for those squares contaminated for only 2 minutes. The dog’s specificity was measured to be 97 percent for both samples of contaminated squares. The positive predictive value was calculated to be 94 percent for the 2 minutes, and 98 percent for the 10 minutes while the negative predictive value was measured at 93 percent for the 2 minutes and 97 percent for the 10 minutes. The skilled searches of the dogs resulted in a 94 percent accuracy for squares contaminated for 2 minutes, and 98 percent for those squares contaminated for 10 minutes. The dogs false signaled, in the form of over-runs and mis-signals during searches performed on carpet squares contaminated for 10 minutes that had been ventilated for 5 to 6 days, or on carpet squares contaminated for 2 minutes that had been ventilated for 2 days. Nevertheless, searches performed on carpet squares that had been ventilated for longer periods of time than those previously mentioned time frames were concluded without any false results by the dogs. This systematic investigation ended after 65 days due to limited time of the dogs and dog handlers to perform regular searches. The dogs belonged to the Hamburg State Police. Figures, tables, references