In the 1980's, the emphasis of police was on surveillance, but the increased use of surveillance in the 1990's caused drug dealers to change tactics and police had to respond appropriately. Difficulties in bringing a successful prosecution against a drug dealer were significant, and the use of informants emerged as a productive police tactic. Further, the Drug Trafficking Offences Act of 1986 and the Drug Trafficking Act of 1994 gave police officers the authority to inquire into the means of any person charged with a drug trafficking offense to establish the extent to which a suspect benefited financially. Police officers must also deal with drug investigations in the club scene and must know how to prepare court files for persons who have been arrested and charged with conspiracy to supply controlled drugs (usually heroin, crack cocaine, and ecstasy). The use of drug support teams to approach the drug problem with consistency is discussed. The author concludes that criminals have responded to police efforts over the past 20 years by using compartmentalized schemes that make evidence collection more difficult; also that police methods will have to continue to develop to meet new demands. 2 figures