Observational field studies suggest that this is a common practice that there is a strong inverse relationship between the strength of the prosecution's case and concessions that a defendant is offered. However, there has yet to be an explicit test of this hypothesis. This study examines the relationship of evidentiary factors to charge reductions using data from the Prosecutor's Management Information System (PROMIS) for the District of Columbia. The analysis indicates that the expected relationship does exist but is not as strong as some suggest and varies by the type of offense. It also suggests that this practice is part of a routine adjudicatory procedure, particularly for property crimes, and that there is a need to scrutinize more closely the fact-finding function of the guilty plea. (Author abstract)