OBTS data are taken directly from the State's Automated Criminal History System (ACHS). All information is entered into ACHS from fingerprint cards, while most disposition data are entered from Department of Justice forms. Dispositions of adult felony arrests were reported by almost 1,100 agencies in 1990. During the 1981-1990 period, more than half of the adult felony arrests resulted in a conviction. Adults arrested for property offenses were more likely to be convicted than those arrested for violent or drug offenses. Of the major arrest offenses examined, burglary had the highest conviction rate. Since 1982, over half of the adult felony arrest convictions have resulted in sentences to probation with jail. With the exception of assault, the most frequent sentence given to those convicted of a violent offense was commitment to a State institution. The proportion of drug offenders sentenced to State institutions was nearly 5 times greater in 1990 than in 1981 (32.4 versus 6.7 percent). Conviction rates were higher in smaller county population groups than in larger county population groups. Appendixes contain a glossary and information on data limitations. Tables and figures