NCJ Number
214951
Journal
Journal of Forensic Identification Volume: 56 Issue: 4 Dated: July/August 2006 Pages: 534-539
Date Published
July 2006
Length
6 pages
Annotation
This article describes the design and findings of a research project whose objective was to determine the factors that influenced the ability of a trained police K9 to sniff out evidence.
Abstract
The authors advise that if a crime scene can be kept secure after the initial crime-scene investigators have completed their search, a trained search dog can be used to conduct one last sweep for undetected evidence, provided that the time frame from the depositing of the evidence to the K9 search does not exceed the particular dog's detection ability. For most dogs, a 16-hour time frame would pose no detection problem. The K9, a German shepherd trained to search for evidence, was able to find bottle caps with a human scent for up to 5 days after they were deposited in the field. He rarely found any of the scent objects after this time period. Over the 5-day period, the dog's detection ability dropped uniformly at a rate of approximately 20 percent each day. Interviews with other K9 handlers found significant differences in the length of time that their dogs were able to locate scent objects, indicating that the abilities of each dog must be tailored to the time-related circumstances of each search. The conditions found to be most conducive to a successful search were at midmorning when temperatures were mild (70-80 degrees F), humidity was lower, and the sunlight created a thermal lift from the evidence object (a bottle cap). This suggests that the search team should pick the most favorable time to conduct an evidence search, so the dog can function at full potential. The search area was a large field several hundred yards long and wide in central Florida, divided into 30' x 30' search grids. Several hundred bottle caps were used as scent objects. 1 reference