Scientists have been able to test for drugs for many years. Early chromatography processes were developed around 1900, but their application to testing urine for drugs did not occur until the 1960's. In the 1970's, immuno-assay technologies were developed. Spurred by rising rates of drug use in the 1970's and 1980's, drug testing in the criminal and juvenile justice system evolved. The first use of urinalysis to assess the drug status of people in jail was reported in 1977 (Mieczkowski and Lersch, 1997).

Within the past 20 years, both the technology for drug testing and the perceived need for it have expanded markedly. Drug testing now is used throughout all components of the criminal and juvenile justice systems. However, it is not applied consistently; that is, the purpose for testing and the extent of its application in justice programs vary. In general, juvenile justice agencies have not employed drug testing to the degree that it has been used in the adult criminal justice system.

With emerging technologies, changing levels and patterns of drug use, rising public concern, and growing political support, drug testing is increasingly used in juvenile justice (Mieczkowski and Lersch, 1997). Drug testing of juveniles can be used for several purposes, including the following:

• Identifying youth who are using alcohol and other drugs.

• Screening for the presence of substances that may pose a risk to the health and safety of a particular youth or others with whom he or she has contact.

• Assessing the risks and needs of youthful offenders and indicating whether there is a need for further evaluation and treatment for substance abuse or other services.

• Helping develop appropriate case plans for youth.

• Deterring the use of alcohol and other drugs by juveniles.

• Supervising and monitoring a youth's compliance with court conditions or program rules.

• Confronting youth who deny -substance abuse or addiction.

• Determining which drugs are presently used by juveniles within the jurisdiction and discerning patterns and prevalence of use in various localities.

• Collecting evidence for prosecution or revocation. (This is rarely done in juvenile justice.)