Congress established some consistency in sentencing by passing statutes that require judges to impose mandatory minimum penalties on defendants convicted of certain offenses. Although judges can increase sentences above mandatory minimum levels, they cannot reduce the minimum to reflect relevant mitigating characteristics as they can under the current sentencing guidelines. Thus, mandatory minimum offenses, which have been uniformly upheld as a legitimate exercise of congressional authority over sentencing, actually encroach further into the domain of judicial discretion than do the guidelines. In contrast, mandatory minimum sentences actually increase the prosecutor's discretion. Contrary to popular misconceptions, however, the guidelines do not transfer authority over sentencing from judges to prosecutors. Judges retain exclusive power to accept or reject plea bargains, to find facts upon which sentences will be based, and to decide the precise sentence within the guideline range. The Thornburgh Memorandum articulates the core policy on plea bargaining: Federal prosecutors should initially charge the most serious, readily provable offense or offenses consistent with the defendant's conduct. Practicalities of prosecution under the sentencing guidelines are discussed that concern charging decisions, plea bargaining, presentence investigations, sentencing hearings, and substantial assistance departures. 28 footnotes