REFORM OF SENTENCING STATUTES HAS RECENTLY EMERGED AS A MAJOR ISSUE OF NATIONAL DEBATE. CRIMINOLOGISTS AND LEGAL SCHOLARS HAVE EXPRESSED DISCONTENT WITH THE EXCESSIVE DISPARITIES IN THE SENTENCES IMPOSED AND SERVED UNDER PRESENT STATUTES. IN ADDITION, MOUNTING PUBLIC DISTRESS IS OCCURRING OVER THE GROWING RATE OF VIOLENT AND PROPERTY CRIMES. THE USE OF MANDATORY SENTENCING AS A MEANS TO IMPROVE THESE CONDITIONS IS EXPLORED IN THIS STUDY. DATA WAS OBTAINED ON A RANDOM SAMPLE OF DEFENDANTS CONVICTED OF SERIOUS OFFENSES OVER A 2 YEAR PERIOD IN THE DENVER, COLORADO, DISTRICT COURTS. THE SAMPLE POPULATION CONSISTED OF 625 PERSONS WHO WERE CONVICTED OF BURGLARY, ROBBERY, HOMICIDE, RAPE, AND GRAND LARCENY; THE SAMPLE REPRESENTED 42 PERCENT OF THE POPULATION AVAILABLE FOR STUDY. FOCUSING ON CRIME-REDUCTION POTENTIAL, OPTIMAL LENGTH OF COMFINEMENT, AND OPTIMAL 'TARGET POPULATION', THE METHODOLOGY INVOLVED RELIANCE ON CAREER HISTORIES TO ESTIMATE THE PROBABLE INCAPACITATION EFFECTS IF OFFENDERS HAD BEEN SENTENCED DIFFERENTLY IN THE PAST. IT IS CONCLUDED THAT MANDATORY-MINIMUM SENTENCE POLICIES CAN REDUCE CRIME THROUGH INCAPACITATION EFFECTS, BUT SUBSTANTIAL INCREASES IN PRISON POPULATIONS WILL BE REQUIRED TO ACHIEVE EVEN MODEST REDUCTION IN ADULT CRIME. FOR A 1-PERCENT REDUCTION IN CRIME, PRISON MUST INCREASE BY 3 TO 10 PERCENT. IT IS CONCLUDED THAT MANDATORY-MINIMUM SENTENCING POLICIES FOCUSING ONLY ON DEFENDANTS WITH PRIOR RECORDS ARE LESS EFFICIENT. GRAPHS, TABULAR DATA, AND FOOTNOTES PROVIDED. (LWM)