Each agency collected different  kinds of measures, which varied in terms of whether they focused on  detection and monitoring or on drug seizures and whether or not they  focused specifically on the agency’s activities in the transit zone. All results data  are classified. We  identified two interagency databases—the FDSS, and the Consolidated  Counterdrug Database (CCDB)—which were designed, among other  things, to improve the accuracy of cocaine seizure data when multiple  agencies participate in the seizures. These seizures ultimately contributed to the totals  reported by the two agencies as measures of their effectiveness in drug  interdiction. Customs’ role in these  seizures included participating in drug-smuggling investigations that  resulted in a number of the seizures; detecting, monitoring, and tracking  drug-smuggling aircraft or vessels; and searching vessels that had been  apprehended by the Coast Guard. Although the FDSS has controls to prevent the same seizures  from being counted more than once, FDSS was not designed to prevent  individual agencies from reporting the same seizures in their own  databases. Quarterly CCDB Meetings May Help Verify the Details of Transit Zone Cocaine Seizures

The CCDB contains information on nearly all air and maritime cocaine  seizures made in the transit zone and is used by DOD, the Coast Guard,  and Customs as a check on the accuracy of their agencies’ cocaine seizure  data. To determine the extent to which we could identify the funds obligated  and assets used for transit zone drug interdiction activities of DOD, the  Coast Guard, and Customs, we interviewed agency and ONDCP budget  officials, reviewed agency budget documents, and reviewed data on flight  hours and ship days from agency data systems. Federal-Wide Drug Seizure System Federal Drug Identification Number  (FDIN). Customs Service: Drug Interdiction Efforts (GAO/GGD-96-189BR,  Sept. 26, 1996).
What GAO Found

The Defense Department (DOD), the Coast Guard, and the Customs Service all interdict illegal drugs--primarily cocaine--from South America. DOD is the lead agency, but all three agencies play a role in monitoring and detecting shipments of illegal drugs. The Coast Guard is the lead agency for apprehending ships that are smuggling drugs, with Customs providing help as needed. The Coast Guard and Customs share responsibility for apprehending aircraft involved in drug-smuggling. GAO could not identify the funds obligated and the number of flight hours and ship days used for drug interdiction in the drug transit zone because the three agencies do not routinely track this information. The results tracked by the three agencies to demonstrate their effectiveness of their drug interdiction efforts in the transit zone varied according to whether they focused on drug seizures or results of detection and monitoring and whether they were specific to the transit zone. Agencies can use several controls to ensure the accuracy of their own cocaine seizure data, such as assigning unique identification numbers to each seizure and headquarters review of data from field units. Although two interagency data systems have been developed to ensure the accuracy of governmentwide cocaine seizure data when multiple agencies participate in a seizure, the two systems do not prevent agencies from counting cocaine seizures in their own databases and annual counts when more than one agency participates in the seizure.