Every weary truck driver knows the highway stops where he can pay $15 for a bag of stimulating amphetamine tabletshe calls them "bennies" or "copilots." Equally knowledgeable is Harold Leap, agent of the year-old U.S. Bureau of Drug Abuse Control and head of its St. Louis office. Disguised as truck drivers, Leap's D-men have bought illegal bennies time and again, but not just to nab roadside peddlers. They aim to buy supplies of bennies wholesale, and thus trace the black-market drugs back to their source.
Last month Leap's agents were able to place an order for 10 million pills at...