The report attempts to determine: (1) why there were apparent discrepancies in the 1999 statistical data generated by the two programs, particularly in the data pertaining to Southwest Asia heroin; (2) why the Heroin Signature Program data showed heroin seizure information for only one U.S. Pacific Coast international airport; (3) whether sufficient samples relating to heroin seizures were being furnished for analysis under the Heroin Signature Program; and (4) the extent to which the Drug Enforcement Administration (DEA) was committed to the Domestic Monitor Program. Discrepancies in the 1999 statistical data were the result of the two programs' data not being comparable. The Signature Program data identified the source of heroin seized at specific U.S. international airports, whereas the Monitor Program data identify the source of heroin obtained through random, undercover, retail-level heroin purchases in specific cities. Signature Program data showed heroin seizure information for only one U.S. Pacific Coast international airport (Los Angeles International) because there were no 1999 seizures at other Pacific Coast airports that met Federal prosecution guidelines. DEA officials responsible for the Signature Program received sufficient samples of the heroin seized by Federal law enforcement agencies but received few or no samples of heroin seized by State and local agencies. DEA is committed to the Domestic Monitor Program and conducts annual field division inspections, which include verification of compliance with Program requirements. 2 enclosures