Brookings County K9 Search and Rescue
Human Remains Detection
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

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).

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

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.  
How HRD Dogs Are Used

VEHICLES - HRD Dogs can check
vehicles that may have been involved
in a hit-and-run or a possible homicide.

remains, when left outdoors, may be
scattered by local wildlife. These
remains may provide clues to
detectives trying to determine the
cause of death or identity of the

dogs, trained for burned remains, can
determine if a body is present in a
burned building, and can also help
define a more specific search area
within the burned debris.

can help detect the location of bodies
that may be under building rubble after
a disaster has occurred.

 - BCK9SAR has specially
trained, experienced dogs that can
assist law enforcement by locating,
often within inches, the precise
location of crime scenes, even if they
have been cleaned up. Contact us for
more information.

experienced dogs that can assist in
locating old clandestine graves.
Contact us for more information.

Links to More Information
Brookings County K9
Search and Rescue
Brookings, South Dakota
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