Tracking Dog Evidence

The following article was forwarded to me from a law journal and offers an interesting look at Dog Tracking Evidence.

WINNIPEG: Police dogs are used for a number of different purposes, from drug and bomb detection to locating cadavers and tracking people. Each dog has their own specialty and training and you need to be careful to distinguish between the two (or ensure that a defence lawyer does not try and use drug detection cases in their challenge of tracking cases, which I believe are distinguishable).

Furthermore, drug detection dogs have not been around as long as tracking dogs. In fact I have found court decisions more than 115 years old. The earliest criminal case found supporting the admission of this type of evidence goes back to Hodge v. State (1893) in Alabama.

In this case a trial witness testified that a dog trained to follow human tracks was used to track the defendant to his home. Defendant’s counsel objected to the evidence given by the witness. The trial court overruled the objection and allowed the evidence to go to the jury. The Alabama Supreme Court affirmed the judgment of the trial court. The state Supreme Court acknowledged that dogs may be trained to follow the tracks of a human being with considerable certainty and accuracy. It held that testimony regarding the tracking by the dog was competent to go to the jury for consideration, in connection with the other evidence, as a circumstance connecting the defendant with the crime.

In Canada, while there are very few cases on point, the seminal decision on dog tracker evidence is R. v. Haas (1962) in which a 5-member panel of the B.C. Court of Appeal upheld the qualifications of a police dog and its trainer to track the accused by scent from the scene of a crime. This decision has subsequently been quoted numerous times, by numerous courts in support of this position. This would include the very persuasive English Court of Appeal in R. v. Montgomery (1966), where Lord Justice Curran stated:

The tracker dog might be aptly described as a tracking instrument guided by a trail of human scent, and its handler as an expert trained to set it on to the trail by the appropriate word of command, and to observe whether it is tracking and whether at any point it has lost the scent it was following. As an expert the handler gives the evidence as to the tracking operation and is subject to cross-examination, as in the present case.

We cannot agree that the dog is in the same position as a person who saw which way the guilty persons went, and who alone could give such evidence and would be subject to cross-examination.

Mr. McCollum has properly conceded that evidence as to the route taken by the three guilty persons is relevant. If such evidence can be given by a trained dog handler using a trained tracker dog, we are of opinion that such evidence is admissible. It was open to the jury to find on the evidence that the tracker dog and its handler were trained and efficient. It was for the jury to give such weight to the evidence as they considered just.

At the moment the Ontario Court of Appeal is leading the way regarding this type of evidence. The most recent case is R. v. West (2005), in which a unanimous court re-affirmed its position from 2002 in R. v. Holmes, which in turn adopted the test articulated by Justice Wein in R. v. Klymchuk (2000). That test requires that before tracker dog evidence is admitted against an accused person, there must be evidence about the reliability of the dog breed and about the particular skills and reliability of the dog as a tracker. The handler must explain the process, sequence, and outcome of the tracking.

In R. v. West, the Court of Appeal excluded the tracker dog evidence because no such evidence was provided. However, in general, the Court has held that the evidence must be reliable. Without attempting to be exhaustive in this regard, the following is a checklist developed by Justice Desmarais of the Ontario Superior Court of Justice in R. v. Ahmed (2004), outlining the circumstances that should exist before dog tracker evidence is allowed to be brought forward in court:

Breed. What is the historical data relating to the particular breed of the dog in terms of their ability to track human scent?

Training. What is the nature of the training received by this particular dog and its handler? The duration of the training program and the variables brought into the program such as terrain, outside influence, or distractions, for example, noises, traffic, other dogs or animals, and so on.

Period of time dog and handler have been together. That goes to the issue of bonding and being able to communicate commands and interpret the dog's reactions.

Operational experiences. The skills exhibited by this particular dog and his reliability in terms of being capable of tracking to a successful conclusion.

Specific information should also be provided as to the number of operational sorties [missions] that this dog has had and the degree of success encountered.

Whether there has been refresher courses for the dog and handler and how both have faired in such courses.

In terms of the specific evidence of human tracking in any particular investigation, it will be necessary to establish the specific conditions which existed at the time, including:

a.the nature of the terrain; for example, forest, park, field, pavement, building, et cetera;

b.the weather conditions, wet, dry, cold, warm, humid and so on;

c.whether the locale where the tracking occurred was contaminated or not -- for example if a scent brought the officer and his dog through a school yard immediately after recess had occurred, this would cause the tracking to be terminated as the scent would, in all likelihood be lost as a result of school children, "contaminating the terrain".

Whether there are contemporaneous or near contemporaneous notes of the tracking.

To this list one should also add:

Previous court cases in which the handler (and the dog) have testified, the findings of the court and, if qualified as an expert, the Judge or Justice who you qualified before.

Any professional associations the handler or the Service is a member of. Often professional memberships and designations provide the officer with regular information and updates on such things as court cases, training issues, areas of concern, competencies, practice tips, etc. Sometimes these associations also have national or international standards or accreditation that members and their dogs must meet.

Corroboration – this would be case specific, but would include anything found or located by the dog/handler that shows they were on the right ‘track’ (i.e. discard items, footprints, torn clothing, etc).


The Courts in British Columbia have also been very active in this area. In R. v. Sherman (1997), one of the more recent decisions from that province, Justice Romilly held that both the dog handler and the dog must be qualified and set out the following criteria to accomplish this:

Dog Track Evidence - Weight to be attached to Dog Track Evidence

Dog track evidence is circumstantial evidence which is admissible if the foundation for the evidence is properly made out; thereafter the only question is the weight to be afforded to it.

Establishing the Foundation

A dog handler should be called as an expert witness and both he and the dog must be qualified. In R. v. Haas (1962), Davey J.A. stated at p.365:

The evidence tendered should not be admitted unless the Crown first establishes the qualifications of the dog and its trainer. It is the dog's propensities and skills that make the evidence of what the dog did admissible, just as it is a witness's qualifications and training that establishes him as an expert and makes his opinion admissible. The qualifications of the dog, like those of an expert, must be proved.

Qualifications

The dog master should be qualified as an expert in:

1. how the police dog responds to human scent;

2. how the police dog communicates his findings i.e. the prosecutor should establish the basis for interpretation of the dog's reactions.

Questions that should be put to the dog master should cover:

a) the training;

b) the length of service in the dog section;

c) experience;

d) number of times the dog master has testified in court and the level of court at which he or she testified.

Questions should also be put to the dog master regarding the training of the police dog which was used; the ongoing training of this dog; the number of investigations; the record of accuracy; and the breed of the dog.

Interpreting the Police Dog's Findings

In this regard the Crown should lead evidence through the dog handler with respect to the propensity of the named dog to track scent over various types of terrain, climatic conditions, and what are the dog's distractions. The dog handler should also lead evidence with respect to the signs or signals which are usually given by the dog at stages of tracking, such as raising his tail, becoming more excited, etc. Evidence should also be led by the dog master about the relationship between himself or herself and this particular dog, the length of time they have worked together, and whether the dog master initially trained this dog. It may be helpful to lead evidence through the dog master about a comparison between this particular dog's propensity to track against other dogs he has worked with.

Reliability of Tracking Dog's Evidence Generally

A foundation must be laid providing the basis for relying on dog track evidence. This should include factors which affect the strength of the scent such as terrain, and whether the scent has been picked up in an urban area or rural area. There should also be evidence as to whether there were any distractions for the dog. Evidence should be led as to whether the scent was being followed on a well-travelled route or a route that is not as well-travelled. The reliability of the scent would depend also on the climate. In some hot and dry weather the scent is dissipated more quickly. Wind also could help or hinder the tracking of the scent depending on the direction in which the wind is blowing. Rain and damp conditions tend to enhance the scent.

Substantive Evidence of the Tracking Issue

Description of the track should be covered by the dog handler. Questions should include the distance covered; length of time; speed at which dog moved; terrain; climate; and distractions.

Factors Corroborating the Track

Factors corroborating the dog track can be crucial to support the proposition that the dog was on the correct track. They include any articles found along the way which obviously came from the crime scene or belong to the accused, footprints and any evidence which relates to the crime in question.


Judicial Notice

While a judge cannot take judicial notice that any particular breed of dog has a greater or lesser propensity to track human scent (this must be proved through the dog handler), judicial notice may be made that humans give off a scent which dogs are able to detect.

Charge to the Jury

In R. v. Haas (1962), at 368 Wilson J.A. (as he then was) stated:

I think that the sort of evidence the court has in this case countenanced must be put before juries with the utmost care and the fullest sort of explanation by the presiding judge. I do not presume to establish a new rule regarding the necessity for or desirability of corroboration, but neither do I want to commit myself to the proposition that this appeal must necessarily have been allowed if there were not, as there were here, other circumstances which, considered with the evidence of the tracking, might justify a conviction ... A jury ought to be warned against the danger of a conviction based only on evidence of tracking by a dog.

Reasonable Doubt versus Remote Possibility

Generally, dog handlers will testify that it is possible for the dog to become distracted and switch from tracking one scent to another. This becomes increasingly important where there is a gap in the track, that is where the track cannot be followed across a highway etc., and the dog must pick up the track on the other side. In such instances evidence must be led of the dog's reaction upon finding the track on the other side of the highway, etc., and the length of time to pick up the track again; any hesitancy in resuming tracking, etc. It is only then that the dog handler could be in a position to give his opinion as to whether the dog is following the same scent. However, a remote possibility that it is not the same scent is not a reasonable doubt and does not mean that the evidence has no weight.

Defence counsel drew my attention to R. v. Rackley (1996) where McKinnon J. qualified a police officer as being an expert in the handling of tracker dogs and allowed to give opinion evidence as to the meaning of his dog's behaviour. His dog was also qualified as being an expert in the tracking of human scent. Because the issue in the case was one of identity and there was evidence that when tracking more than one human scent his dog might choose one scent over another without a logical explanation, the learned justice placed limits on the opinion evidence that could be given by the dog handler. At p. 400 he stated:

In the result, I find as follows:

(1) Constable Leach will be qualified as an expert in the handling of tracker dogs.

(2) He may testify as to his opinion on the ability of tracker dogs to detect human scent and the training which may be undertaken to reinforce this ability.

(3) He may testify as to his observations as to what his dog did on the evening of 23rd March, 1995.

(4) He may testify as to his opinion as to the dog's ability to track human scent as distinguished from other scents.

(5) He may not venture opinions as to which particular human scent the dog is tracking because on his own admission he cannot account for this.

In my view Rackley is distinguishable from the case at bar. In the case at bar there is no evidence that when tracking more than one human scent his dog, Alsan, might choose one scent over another without a logical explanation. In fact there is evidence that, apart from the police officers and Mr. Anderson, the person who left the truck running was the only other person in the vicinity at the time.

After reviewing the principles of law on the issue of dog tracks, I am satisfied that the evidence of the dog track was admissible cogent evidence which has been corroborated in many particulars.

A WORD OF CAUTION - In R. v. Mohan (1994), when ruling the polygraph and its operator were not reliable expert witnesses, the Supreme Court was concerned that such evidence would be “dressed up in scientific language which the jury does not easily understand and submitted through a witness of impressive antecedents [such that] this evidence is apt to be accepted by the jury as being virtually infallible and as having more weight than it deserves”.

While dog tracking has more than 100 years of proven court history and the entire population is familiar with dogs and their abilities (unlike the polygraph machine), where you might need to use scientific language to explain something – keep it simple.