Evidence Recovery part II
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By Senior Master Instructor Chris Aycock

The last time we talked about evidence recovery we focused on the technical aspects of the work: environmental scent, time, scent assumption, Etc. Now it’s time to but that information to practical use by apply our knowledge to training the canine to detect evidence.

There are two primary processes for teaching a canine to detect evidence.  We will discuss them both here. The first is more of a direct approach, allowing the dog to associate the evidence with a specific command and using the scent theory to allow the sessions to improve. The second method allows the trainer more of a slight of hand approach whereby the dog isn’t really focusing on the article itself but rather indirectly encountering it while on a track or area search, and registering it as foreign to the environment, then cataloging the type of evidence as positively reinforced - storing the scent of it for latter use.


Note: Training begins with short grass and increases rapidly.  The final location for optimal results is along side a highway or trash strewn roadway.

A. The trainer selects an object (preferably a type of realistic evidence object: firearm, knife, magazine cartridge, shells, casings, wallets, clothing, Etc.) (note: I have never seen a suspect drop a piece of leather on a live track. Keep it real.

B. The trainer takes the dog out to a safe location and presents one article per each training session.  The trainer shows the article to the canine and tosses it a few times for a friendly game of fetch. 

C. Once the dog is interested in playing with the object and the drive increases, the trainer secures the canine (sit/down stay, vehicle, crate, back-tie, Etc.) and tosses the object out in an area not saturated with
The handler/dog scent.  Then, the dog is asked to retrieve the item with a chosen command that was used during the fetch.  Once the dog completes the process 10 times without assistance, the trainer is ready to repeat the training with each of the evidence items in his/her bag.

D. As the dog progresses in searching, command recognition, and ability, the trainer will want to conduct the training as a testing format.  Start slow.  If problems arise, simple back the training up and allow the dog to mature his ability into the formal, testing search.

E. The testing search is set up in a 60 x 60 ft environment with grass about 10 inches high.  The trainer will keep dog secured (not seeing the items or handler) and will follow a single line down the center of the area.  As the trainer walks, he tosses the evidence items to the left - then right - at varied distances.  The number of items can vary but typically 4 - 8 are adequate.

F. The canine is brought to the area.  The handler issue the command and the canine begins to search.  The objective is to:
1. Not miss any items. 
2. Complete the search in less that 15 minutes.

Once the canine retrieves each item (or sits/downs on it), the trainer should reward with strong praise and physical attention.  Then, the trainer should remove the item, secure it away from area, return to area and continue search.
Note: make certain to secure the item from view and back of motivation during the securing of item or the dog will think you are planting the item for him to go find.

Should the canine have trouble, do not become frustrated. Instead, simply turn the testing into a play session and have fun.  Then back up the training and slow down the progression until the dog is ready to try again.

G.  Once the canine is working locating the evidence properly, along the roadsides and during the testing, the trainer can feel confident that the dog will be of usable service for live evidence recovery; particularly, where the types of items trained with are being located.


This is a preferred method in my training because it lends itself strongly to live situations and is extremely applicable for evidence discarded during a suspects flee.  Unlike a testing/certification/trial type of field activity, whereby the evidence is placed in a optimal environment, indirect contact immediately places the dog in realistic position to scent for evidence, balancing with drive for the search.

Note: For simplicity, this training will be based upon tracking.  However, the same method could also be used with non-tracking dogs in an area search format.

THE SECRET! During training tracks use evidence instead of a toy!

A. The trainer lays training tracks.  At the end of the tracks the handler or helper places an evidence item. 

B. The trainer tracks the dog for either handler laid or quarry laid end and follows the exact same procedure as tracking.

C. As the dog approaches the item, the handler will slow the dog and allow the dog to process the scent more thoroughly.  Upon the dog locating the item, the handler should then praise the dog enthusiastically and allow the dog an immediate toss/fetch of the item.  The track is over at this point!

D. Once the dog is locating evidence items on the track without having to be slowed or prompted, the trainer will allow the dog to find the evidence, remove it from the dog’s control, secure it with backup or in an evidence type bag (eliminates scent) - and asks the dog to continue tracking.  As the track ends, the dog may locate a decoy or further evidence. This prevents the dog from searching only for evidence.

E. Once the dog is making progress in step D - the trainer will then want to be certain to add additional items to the mix.  In addition, the trainer or decoy, should begin to discard items to the side of the track as opposed to directly on the track.  Remember, fleeing suspects throw and toss evidence away from them as they run. 

F. The trainer should encourage the dog to locate as much evidence as possible along the track - while moving towards the decoy’s position.  Any evidence missed should be found on the return from the capture of the decoy by conducting evidence sweeps along the sides (3-15 feet) of the original track. The dog should be encouraged to located the items and allowed a fetch of them, once they are found.

G. Tracks should be increased in both difficulty and reward by training in realistic areas: roadways, parks, Etc. where there is frequent items crossed during the track.

As with all K9 training, success is more a matter of dedication and training time than anything else.  However, knowing the correct techniques that have proven successful does help. 

I have used both of the above methods for over two decades of training.  Though I prefer Process 2, I have also found Process 1 very rewarding.

Good Luck…Keep Training.

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