Canine substance detection

Definition: Work carried out by trained dog and handler teams to discover contraband items and hazardous materials associated with criminal activities or security threats.

Significance: Well-trained dogs, with their natural scent abilities, are able to locate illegal narcotics and explosive and flammable chemicals expeditiously, whereas humans and technological search devices might overlook these materials or discover them only slowly. Canine substance detection has proven useful in the apprehension and prosecution of lawbreakers.

For several centuries, dogs have assisted humans in seeking forensic evidence related to crimes, including tracking missing people and finding human remains. Law-enforcement agencies’ use of canines to detect illegal drugs, explosives, and accelerants intensified during the late twentieth century. Although other animals, such as rats, also have keen smelling abilities, law-enforcement personnel prefer dogs because of their appeal to many people, their ability to work in congested areas and shift quickly to additional sites, and their willingness to obey commands.

The scent capabilities of canines significantly exceed those of humans. A dog’s sense of smell is enhanced by the presence of approximately 220 olfactory receptors in the nose. Mucus covers these receptors, enabling them to capture molecules released by chemicals when the dog sniffs nearby. Information from these molecules reaches the dog’s brain through a nerve, alerting it to the presence of specific substances. These qualities make dogs ideal for law-enforcement use in detecting various illegal and dangerous substances.

Training and Certification

Law-enforcement personnel procure detection dogs from various sources. The Australian Customs Service Detector Dog Breeding Program provides stock for U.S. detection dog breeders, particularly the Transportation Security Administration (TSA) Explosive Detection Dog Program and Auburn University’s Canine Detection Training Center (CDTC) at McClellan, Alabama, which supply detection dogs for governments at various levels. As the sole training program of its kind affiliated with a veterinary school, the CDTC benefits from studies conducted by veterinarians and scientists at the Canine and Detection Research Institute. The government and university programs focus on refining detection qualities in Labrador retrievers, Belgian Malinois, and shepherd breeds considered to be behaviorally reliable and physically sturdy.

Detector dog selection and training are rigorous, and only the most competent canines are approved for deployment to law-enforcement agencies. Several government facilities, the CDTC, and private businesses train canines and handlers for substance-detection duties. The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) Canine Training Center at Front Royal, Virginia, where the U.S. Customs and Border Protection (CBP) also has a canine training site, certifies dogs that complete successfully national odor recognition testing. The U.S. Drug Enforcement Administration (DEA) licenses the use of drugs at government and approved private training facilities. ATF also trains canines to detect explosives, working with forensic chemists to choose appropriate explosives for effective training.

According to their individual intended purposes, the dogs are trained to detect and distinguish the scents of many substances, ranging from chemicals found in heroin, cocaine, marijuana, and methamphetamine to explosive nitroglycerin, trinitrotoluene (TNT), and smokeless powders. In ATF training for arson dogs, the dogs learn to detect specified odors of gasoline, kerosene, and other accelerants.

Detection and Effectiveness

Many law-enforcement officials consider the use of canines to be the most efficient and effective method of detecting narcotic substances, resulting in arrests of suspects. Substance-detection dogs are taken to public and private locations, including schools, businesses, prisons, stadiums, and motor vehicles, where they seek the scents they are directed to detect; they alert their handlers to any substance finds by scratching, barking, or sitting.

At border checkpoints, CBP and U.S. Department of Agriculture detection dogs search for illegal substances, including harmful agricultural products. For example, in 2004, U.S. customs authorities using substance-detection dogs conducted 11,600 narcotics seizures totaling approximately 1.8 million pounds of narcotics as well as 6,500 pounds of illegal plant and animal products.

Substance-detection dogs that locate explosives effectively defuse potentially hazardous situations. The U.S. Department of Homeland Security oversees canine substance detection in its antiterrorism work; this work is conducted by CBP and TSA dogs that are trained to locate dangerous chemicals and bombs. Because such substances are often hidden in sealed containers and in concealed areas, dogs can swiftly find them where humans might not easily detect them. Explosives experts provide information on the chemicals that have previously been used by terrorists, and the dogs are trained to detect those substances.

As part of enhanced security measures in the United States and elsewhere, canines sniff luggage, packages, mail, and cargo for illegal substances, explosives, and bombs at airports, train stations, ports, and crowded areas that could be terrorist targets. Dogs are used to examine industrial sites for potential sabotage. The ability of dogs to detect explosive chemicals has also led to their use in arson investigations to find accelerants at sites of suspicious fires. As new chemical threats emerge, researchers and trainers are constantly refining their training procedures to expand the abilities of substance-detection dogs to detect chemical and narcotic substances.

Despite detector dogs’ high accuracy rates, many courts disregard evidence located by dogs through scent detection because this method lacks a sufficient scientific basis. Some judges, however, have ruled that search warrants can be issued based on detection dogs’ alerts, as in the finding in United States v. Trayer (1990), a case that involved a dog alerting to drugs at the door of a train compartment.

To reinforce legal acceptance of the forensic contributions of detector dogs, researchers are attempting to gain a better scientific understanding of canine scent-detection capabilities. Scientists study handler-canine interactions, canine behavior, and environmental factors to try to find ways to improve dogs’ scent-detection training and performance. Law-enforcement agencies consistently evaluate and recertify substance-detection canines and their handlers, removing from service those that do not perform adequately and might discredit canine substance detection as a forensic tool.

Bibliography

Bidner, Jen. Dog Heroes: Saving Lives and Protecting America. Guilford, Conn.: Lyons Press/Globe Pequot Press, 2002. Presents examples of canines performing police and customs work, including ATF detection dogs that search for drugs and bombs.

Bryson, Sandy. Police Dog Tactics. New York: McGraw-Hill, 1996. Comprehensive text written by a police dog trainer and handler. Includes sections on drug searches and the detection of explosives and accelerants.

Derr, Mark. “With Dog Detectives, Mistakes Can Happen.” The New York Times, December 24, 2002, p. F1. Relates some incidents in which detection canines falsely alerted to locating substances and examines the reasons for dogs’ scenting errors.

Needles, Colleen, and Kit Carlson. Working Dogs: Tales from Animal Planet’s K-9 to 5 World. Photographs by Kim Levin. New York: Discovery Books, 2000. Profiles several drug enforcement, arson, police, and customs inspector dogs.

U.S. Congress. House. Committee on Homeland Security. Sniffing Out Terrorism: The Use of Dogs in Homeland Security. Washington, D.C.: Government Printing Office, 2007. Transcript of statements made by canine detection trainers, handlers, scientists, and law-enforcement representatives at a congressional hearing held on September 28, 2005.