The ignitable liquid used in all cases for this study was unleaded, regular-grade gasoline. The gasoline was stored in a closed container and used within 24 hours of its purchase. Three types of footwear were used: fire boots, work boots, and tennis shoes. The footwear was cleaned, and trained canines were used to verify the absence of materials that would elicit a positive response from the dog, thus verifying a lack of contamination prior to the field experiment. The walking surfaces used for the study were composed of concrete and standard carpet and padding. The field experiment involved establishing the testing area, pouring a specified amount of gasoline at the designated "pour location," and stepping into the "pour location" and walking the length of the testing area. Following the "tracking" process, the dogs worked the scene with their handler/trainer. Canine response was documented, and then samples were secured for transport to the testing laboratory. The data collected and analyzed indicate that "tracking" does not produce false-positive lab results. In a few cases, canines responded to contamination, but laboratory testing, which is the definitive indicator, did not produce positive results. 5 figures, 1 table, and 11 references