Efforts to control gun violence increasingly rely on identifying and closing channels by which firearms flow from the legal market into criminal hands. Of 83,272 federally licensed firearms dealers in 1998, 1020 (1.2%) were associated with 57% of all firearms for which the US Bureau of Alcohol, Tobacco and Firearms (BATF) conducted a trace (a determination of the chain of ownership, usually in connection with a criminal investigation). The Clinton administration is now requiring dealers linked to more than 10 firearm traces in 1999 to undergo more intensive surveillance. Opponents contend that this is unfair because the number of firearms traced to an individual dealer simply reflects that dealer’s sales volume. We report preliminary results of a test of this hypothesis.