The analysis of controlled substances is a mature forensic science discipline and one of the areas with a strong scientific underpinning. The analytical methods used have been adopted from classical analytical chemistry, and there is broad agreement nationwide about best practices.14 In 1997, the U.S. Drug Enforcement Administration and the Office of National Drug Control Policy co-sponsored the formation of the Technical Working Group for the Analysis of Seized Drugs, now known as the Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG). This organization brings together more than 20 forensic practitioners from all over the world to develop standards for the analysis and reporting of illicit drug cases. Their standards are being widely adopted by drug analysis laboratories in the United States and worldwide.

Sample Data and Collection

Controlled substances typically are seized by police officers, narcotics agents, and detectives through undercover buys, raids on drug houses and clandestine drug laboratories, and seizures on the streets. In some cases, forensic chemists are sent to clandestine laboratory operations to help render the laboratory safe and help with evidence collection. The seized drugs may be in the form of powders or adulterated powders, chunks of smokeable or injectable material, legitimate and clandestine tablets and capsules, or plant materials or plant extracts.


Controlled substances are analyzed by well-accepted standard schemes or protocols. Few drug chemists have the requisite botanical background to identify any common illicit plants other than marijuana; thus, in cases that require botanical identification, the assistance of outside experts is enlisted.

Sampling can be a major issue in the analysis of controlled substances. Although sometimes only trace amounts of a drug are present (e.g., in a syringe used to inject heroin), at other times there are hundreds or thousands of packages of drugs or very large bags or bales. SWGDRUG and others have proposed statistical and nonstatistical methods for sampling,15 and a wide variety of methods are used.

Most controlled substances are subjected first to a field test for pre-


See F. Smith and J.A. Siegel (eds.). 2004. Handbook of Forensic Drug Analysis. Burlington, MA: Academic Press.


Scientific Working Group for the Analysis of Seized Drugs (SWGDRUG) Recommendations. Available at

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