Under court orders in past and pending cases, the Maryland State Police maintain a uniquely detailed, publicly available database on the stops and searches they conduct on Interstate Highway 95. In this article we present a comprehensive review of those data, from 1995 through mid-2000, and discuss the problems that are inherent in using official records to study police conduct. We conclude that the Maryland State Police plainly do use race and ethnicity to decide who to stop and who to search, apparently in an effort to increase the tiny proportion of stops that lead to arrests of drug traffickers and to seizures of large quantities of illegal drugs. As a factual matter, it is unclear how this effects drug seizures, since our knowledge of the drug trade is limited to information derived from racially discriminatory police investigations. As a legal matter, the practice is clearly unconstitutional. Fourth Amendment doctrine is ambiguous, but there is little doubt that this form of racial profiling violates the Equal Protection Clause. More important, racial profiling on the highway has become politically unacceptable, and remains so even with the heightened concern about security after September 11, 2001. It is easy to see why. Not only does this practice victimize and humiliate thousands of innocent minority drivers, but it serves no positive function of consequence, since the drug interdiction program in which it occurs has no discernable effect on drug trafficking.