THE MAIN GOAL OF THIS STUDY WAS TO DETERMINE RATES AT WHICH CRIMES AND OFFENDERS DROP OUT OF THE SYSTEM AS A CASE PROCEEDS THROUGH THE FOLLOWING SEQUENCE: REPORTED CRIME, ARREST, COURT DISPOSITION, CONVICTION, AND INCARCERATION. DATA WERE LIMITED TO FELONY OFFENSES COMMITTED BY ADULTS, WITH EMPHASIS ON FBI CRIME REPORTS PART ONE OFFENSES OF MURDER/MANSLAUGHTER, FORCIBLE RAPE, ROBBERY, AGGRAVATED ASSAULT, BURGLARY, LARCENY, AND MOTOR VEHICLE THEFT. OFFENDERS STUDIED WERE NOT ALREADY IN THE CRIMINAL JUSTICE SYSTEM WHEN ARRESTED. RESULTS INDICATED THAT 60 PERCENT OF ADULTS ARRESTED AND CHARGED WITH FELONIES WERE CONVICTED, AND 15 PERCENT WERE INCARCERATED. THOSE SENTENCED TO PRISON SERVED AN AVERAGE OF 23.4 MONTHS PRIOR TO DISCHARGE OR RELEASE ON PAROLE. APPLYING NATIONAL CRIME NONREPORTING RATES TO IOWA, RESEARCHERS CONCLUDED THAT FOR EACH 1,000 PART ONE FELONIES COMMITTED, 956 CASES DROPPED OUT DUE TO NO REPORT OR NO ARREST, AND 31 DROPPED OUT DUE TO NO COURT DISPOSITION OR NO CONVICTION. AS A RESULT, ONLY 13, OR 1.3 PERCENT, OF EACH 1,000 PART ONE CRIMES COMMITTED RESULTED IN A SENTENCE OR INCARCERATION. THE RATE WAS 7.6 PERCENT FOR VIOLENT CRIMES AND ONE PERCENT FOR PROPERTY CRIMES. ATTRITION RATES BASED ON ARRESTS AND ON CRIMES REPORTED ARE ALSO PRESENTED. EXTENSIVE FLOW CHARTS, TABLES, FIGURES, AND FOOTNOTES ARE INCLUDED. FOR RELATED VOLUMES IN THIS SERIES, SEE NCJ 59516-59519. (CFW)