Brookings County K9 Search and Rescue

HRD Basics

 

HRD or Human Remains Detection Dogs (also known as Cadaver Dogs) requires special training for both the handler and the dog. HRD K9 Handlers do this work to help parents, family and friends answer the questions, What happened to them? and Are they alive or dead? Until closure, the family will always wonder and will always ask those questions. When a person passes away, their unique body scent changes through the process of decomposition into the generic scent of human remains.

 

HRD dogs are trained to locate and indicate when they smell that odor. Trained indications must be passive, such as a sit or down. The indication should not disturb the human remains in any way. Odor can consist of actual physical tissue, body fluids or residual odor. Residual odor can mean the body was there at one time, but later moved. Ground, wood, stone, carpet can all absorb human remains odor. HRD dogs can detect the odor even without any visible signs. HRD dogs are trained to detect human remains in various stages of decomposition up to and including skeletal remains. HRD dogs have indicated on graves over 100 years old.

 

Brookings County K9 SAR does not train with, nor does it endorse training with, pseudo human cadaver scent or pig tissue. Our HRD dogs train with the real thing, so they are able to do the job reliably. HRD dogs are routinely proven off (not alerting to) animal remains, methane gas and glass jars (or other training  containers).

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Water Recovery

 

Underwater searches pose many hazards to divers and searchers. Hazards such as water depth, temperature, current, visibility, underwater trees, snags, obstructions and so on. The more divers have to ascend and descend the more dangerous it is for them. Also, the more searchers have to comb the shorelines, cliffs and sand bars the more dangerous it is for them. More and more, Law Enforcement and Emergency Management agencies are calling in other resources such as Side Sonar and Underwater Cameras. Newer side scan sonar systems have been developed using ultrasound technology which greatly increases resolution. Working together with search dogs, these resources can get the job done quickly without putting divers and searchers in danger for extended periods of time.

 

How do dogs detect scent from water? When a person drowns and the process of decomposition starts, they give off liquids and gases. These liquids and gases rise to the surface of the water. Gaseous molecules will evaporate into the air, where dogs can detect it on air currents. Insoluble molecules will float on the top of the water, where dogs can also detect them. How can dogs be deployed? Water Search Dogs can usually work from a boat, from the shoreline, or while swimming in the water. When working from a boat, the handler and dog usually work in the bow. The dog will usually display a change in behavior when in scent. Some may jump from the boat and swim to it. Others may bark when they are right on top of it. Coming back later and rechecking the area with another dog or the same dog, will confirm the site.

 

Side Sonar can be brought in to see if anything is on the bottom. If the person is spotted, diving teams can then be sent down to recover the body. Working from shoreline, dogs are usually worked on the down wind side, so the scent is blown across the water to the dog. Most dogs will swim out to the source. Once in the water, the dog's nose is still working and may change direction in the water if he picks up stronger scent. Here again, another dog or the same dog is brought back to confirm the site.

 

Why are you confirming the site? Most handlers trust their dog to indicate in the right spot but, before putting a diver down and for the safety of the diver, it is always a good idea to confirm the site.

 

What type of boat is needed for water searches? Usually a boat with a flat bow (like a Jon boat). It has a great platform that allows the dog to sniff the water easily. Some teams use inflatable boats or Zodiacs. Most boats are run with electric trolling motors as the speed must be very slow or they use oars. Powered boats can be used, but you must be careful that the exhaust or fumes from the engine is not blowing in the dog's direction. In shallow water, it may be necessary to use a pole to propel the boat forward.

 

What is float time? After a human body has been submerged for so long, gases build to a point where the body will float to the surface. After the gases are released, the body will sink again to the bottom. Float time is primarily dependent on the temperature of the water.

 

Where do they usually find drowning victims? In lakes or ponds, the Place Last Seen or Last Known Point is critical. They almost always drop straight down. For each one foot vertical descent they move one foot horizontally. On rivers and streams, based on the Place Last Seen or Last Known Point, they are almost always found within one mile downstream. Flooding rivers or streams are a different story. Some may go as far as 25 miles downstream.