Masters of Scent Discrimination

Centuries before little Jimmy ever called out to Lassie, dogs were used to find things that man can't smell or see. Certain breeds: Bloodhounds, German Shepherds, Retrievers and Labradors are known for their tracking skills.

The dogs are broken into two categories: air scenting and trailing. Although some dogs are cross-trained, some search and rescue (SAR) experts caution it is better to keep narcotics' dogs looking for drugs and cadaver dogs looking for bodies.

A trailing dog (typically a Bloodhound), will pick up a scent on the ground and track it to the person or body. According to an information packet published by the Martha's Vineyard K-9 Unit, headed by Gina Hayes, the human body sheds 40,000 old cells each minute as new ones are made. These cells are acted upon by bacteria once they hit the air or ground, giving off a gaseous odor unique to that individual.

This type of scent is not the same as that from sweat. It is a lingering odor that can only be trailed by a dog, often called "forgotten evidence" because it can't be seen or smelled by humans.

Scents last longer in colder weather, but can be affected by time, wind and precipitation. Dogs have been known to follow trails that are 10 days old, even tracking people along highways, where car vents let the scent escape from an automobile.

It is the handler's job to read the dog's signals, factor in the variables, and interpret the dog's movements. "You employ the dog in the manner in which it should be and try not to compromise the dog and lessen it's efforts," said Roger Titus, a member of the National Police Bloodhound Association (NPBA) who lives in New Jersey.

Titus prefers Bloodhounds for tracking people. "In football, if you have a guy who can run fast, you give him the ball and let him run. The only thing a Bloodhound does is find people. That's what you should use it for."

Marcia Koenig and Andy Rebmann, residents of Redmond, WA, are referred to by virtually all SAR people as experts in the field. Their K-9 Specialty Seach Associates company sponsors seminars and schools in such areas as Advanced Cadaver Search and Trailing for the Real World.

All SAR people stress the importances of training, not only for the dog, but the handler. "It helps to have a person to learn from," said Koenig. "It puts a picture in your mind of what the dog should be doing."

Beyond the SAR training, experts recommend a background in police procedure, evidence preservation and criminology. "It's an awesome responsibility when you get that call to find a missing person," said Titus. "Someone with no background in police work and criminology can mess up an investigation and accidentally destroy evidence."

Hayes agress. She has spent $30,000 of her own money going to school. Currently a police officer on the West Tisbury force, she considers it money well spent. "My testimony at a trial is accepted. I can understand (both the police and civilian) sides because I've been on both sides. The training will probably never be paid back financially, but there is another kind of reward in this work."

Jeanne Kauffman, a Hingham resident and member of the all-volunteer Search Dogs Northeast group, said that tracking felons isn't as rewarding as finding a missing child. On one search, the dog didn't find the child but did eliminate a great deal of area, freeing the human searchers to look in specific locations.

"To me, that is just as much of a success story. One dog can cover the area that a dozen people could. And with dogs working at night when most of the searchers aren't there, a lot more can be accomplished."

For Hayes, whose two Bloodhounds Rosie and Maggie are used in missing person, drug and rape cases, her purpose isn't to be the heroine of the day but to solve the mystery. "If my dog can't pick up the scent, I'll call in another dog. The main objective is always to find the person."

Her most satisfying case was a lost nine-month old baby. Hayes was worried about the dog's reaction when she found the baby, since Bloodhounds are trained to jump up on the person, giving the police a positive identification. "My dog went in there and belly-crawled to the baby, as if she knew what to do. The child was alive, unharmed and laughing."

In rape cases, the Bloodhounds sniff the hand of the victim. These "masters of scent discrimination," as Hayes calls them, are able to seperate the scent of the suspect from the victim and then go off to find the suspect.

In the case of cadaver searches, the dogs are equally impressive. Dogs have been known to find bodies under water, made easier because water is porous, buried in cement, or up in trees. The dogs are put through sequentially harder training, helping them adapt to any given situation.

Kauffman calls it "the prey without the predator training." She said it is just as important for the trainer "to have strong map, compass and climbing skills to work with the dog effectively."

Hayes waits until the dogs are about six months old and begins with simple trails of a person a few feet away, building up to miles later. "You have to let the dog tell you what he is best at," said Hayes, whose younger dog, Maggie, happens to be good at narcotics searches, an unusual choice for a Bloodhound.

"These types of dogs are big, huge and awkward. They're normally not used to find drugs because they can't get into tiny spaces easily," said Hayes.

The amount of information on SAR is vast. A simple input of those three words into any Internet search engine yields volumes of Web pages and information about SAR groups throughout the country.

For those who want to call in the dogs, calling the local police department is the first step. From there, either the State Police Canine Unit of 28 dogs or another SAR agency can be contacted. Legitimate, criminology-conscious SAR people will wait for the authorities before stepping in.

"If someone is missing, you want to use all the tools in the toolbox, from the police to the dogs," said Titus. "The only thing we want to do is find the child, give it to its mother and go home. That's our job."

What do you do when someone is missing? Here are tips from Gina Hayes on the correct steps for parents or family members to take:

For parents who want to teach their children what to do when they are lost, follow the advice of the Hug A Tree Program, put out by the National Police Bloodhound Association. These tips were followed by a trio of boys lost in the Dartmouth area a few years ago, which resulted in a happy ending for all three families.

Police and NPBA members tour schools, introducing children to the Bloodhounds and letting them learn about the dogs. "We send five or six children out into a supervised area. The kids are always amazed that the dog only finds the one it was told to find," said Hayes. "This program helps the kids have no fear when a great, big dog comes to find them."

The NPBA advises children to "hug a tree" when they are lost, basically stay put until someone finds them. "If you want to make a Bloodhound's job difficult, just keep moving," said Hayes.