Through a process of elimination, this article narrows down the possible explanations for this decline to a substantial shift in the way prosecutors and judges perceive and carry out their functions. It shows that the prison population has been reduced not by passing shorter sentences, but by remanding and sentencing fewer offenders to custody. Initiated by a fundamental questioning of the efficacy and moral legitimacy of pre-trial detention, especially for young offenders, a kind of perestroika is occurring in the West Germany criminal justice system. The article concludes with some suggestions for how the United Kingdom could learn from recent developments in the Federal Republic of Germany. 8 tables, 1 figure, 8 notes, 22 references. (Author abstract)