This report in three volumes is the result of an analysis of material submitted to the EMCDDA in the period 2000–01 on the sources of law enforcement and criminal justice information in Member States. At the time of the study, the reliability and comparability of many of these statistics was unknown, and their value as indirect indicators of drug trends was therefore unclear. The project aimed to gain an insight into the context, recording practices and methodological characteristics of available law-enforcement data. In addition, it also sought to obtain more information on the specific populations coming into contact with law-enforcement institutions such as arrestees or prisoners. The 'Information map on law-enforcement sources' instrument was developed for this purpose, filled in by each Member State through its Reitox national focal point and provided to the EMCDDA for comparative analysis.