> By the end of 1995, distributors across the U.S. had sold about 1,000 Quadro Trackers to customers including police departments in Georgia and Illinois and school districts in Kansas and Florida. When Ronald Kelly, the agent in charge of the Federal Bureau of Investigation’s office in Beaumont, Tex., learned that a local narcotics task force had bought one, he attended a demonstration in which a Tracker was used to find a brick of cocaine. He wasn’t impressed. “I paid reasonable attention in eighth grade science,” Kelly says now. “I pronounced this bulls—.”

In 2001 the new device was almost sold in Denver, except someone conducted a double blind test which the device obviously failed.