Background:
In Washington state, CPT expert Mark Spivak provided consulting services for a criminal defense attorney whose client was charged with larceny based on the tracking and scent discrimination actions of a police K9 dog. A K9 officer started his dog at the location of a burglary, whereupon the dog allegedly tracked ground scent through a variety of surfaces until locating the defendant. I wrote “allegedly,” as the officer did not turn on his body cam to video the track.
The defense attorney needed to learn more about the biological and procedural operation of tracking/trailing dogs. He also wished advisement regarding what evidence to request in a demand for discovery.
Requested Evidence:
The resultant demand included requests for:
a) policy manuals and regulations regarding the training and handling of K9 dogs;
b) certifications obtained by the dog and handler;
c) results from K9 certification tests;
d) detailed K9 training logs covering a specified 6-month period;
e) field logs reporting on the actual use of the dog for scent discrimination purposes and detailing the dog’s mission and outcome (i.e., person found, track abandoned, positive alert for drugs, no alert, contraband found, no contraband found, et al.);
f) disciplinary records for the dog and handler;
g) body camera and/or car cam video;
h) police reports; i) witness statements;
j) reports regarding physical evidence acquisition and analysis; and
k) veterinary records for the dog.
Tracking Evidence Analysis Considerations:
There are two main considerations regarding canine olfaction. First, the dog’s biological ability to detect a target odor. Second, the dog’s cognitive ability to accurately identify and discriminate the target odor.
Many environmental variables can affect biological factors. Pertinent environmental variables in a tracking situation include temperature, humidity, wind strength, wind direction, ground substrate type, the smoothness or hilliness of terrain, cross tracks, initial odor strength, odor duration, and odor degradation. Germane cognitive factors include training history, experience in similar environmental conditions, historical accuracy in similar environmental conditions, experience with similar odor origins and types, and historical accuracy with similar odor origins, types, and conditions.