The 7 Crime Index offenses of violent crimes (murder and non-negligent manslaughter, forcible rape, robbery, and aggravated assault) and property crimes (burglary, larceny-theft, and motor vehicle thefts) are analyzed in terms of longitudinal trends, geographic patterns, and detailed characteristics of both offenders and offenses. In addition, comparisons are made between adult and juvenile arrest patterns and trends in arrests over time. Caseflow analyses for both the adult and the juvenile justice systems are provided. Data indicate that reported Crime Index offenses have declined considerable from 1971 to 1978. The annual totals of Crime Index offenses were roughly between 50,000 and 60,000 and were largely a function of property crime, which comprised approximately three-fourths of reported offenses. Total violent crime experienced a gradual downward trend from 1971 to 1978. The exception was a rise in 1975 due to an increase in robberies. The longitudinal trend of property crime from 1971 to 1978, although essentially downward, displayed more fluctuations than did violent crime. Larceny-theft was the major component of both property crime and the Crime Index total. The greatest decline for any of the Crime Index offenses was in the number of motor vehicle thefts, which decreased by 63.4 percent from 1971 to 1978. The monthly trend of reported Crime Index offenses did not evidence much variation other than an increase in the summer months with a peak in August; the fewest number of offenses was reported for January and February. The daily trend of Crime Index offenses was marked by a high on Friday for property crimes, and on Friday and Saturday for violent crimes, and a low on Sunday for all property crimes and robbery, one of the violent crimes. In comparison with the surrounding jurisdictions in Northen Virginia and Maryland, the District continues to exhibit the highest crime rates, particularly for violent stranger-to-stranger offenses. A detailed discussion of 1977 and 1978 data is included. Appendixes contain definitions of offenses in uniform crime reporting and additional tabular data. (Author abstract modified).