Robberies with firearms declined 18.5 percent in the 7 months following the June 1982 effective date of mandatory sentencing compared to the same period in 1981. While total robberies declined 4.4 percent, strong-arm robberies increased 5.1 percent. This suggests the law deterred some firearms use in robberies, but a displacement into strong-arm robberies also occurred. While aggravated assaults with firearms decreased 6.5 percent in the study period compared to 1981, there is evidence of a net displacement to knife assaults, which increased 6.9 percent. The decrease in 1982 assaults with firearms also may be a continuation of a trend begun in previous years. Arrests for drunk driving continued to increase after the mandatory jail sentence law. Alcohol-related fatal accidents decreased by 7.3 percent in 1983, but had decreased 16.9 percent in 1982. All alcohol-related accidents declined by 3.6 percent, making 1983 the first reversal of a slow but steady upward trend that prevailed from 1978 to 1982. Admission of DUI offenders to county jails increased by 130 percent in 1983, but many admissions received very short sentences. The daily DUI population in county jails rose from 101 in 1981 to 210 in l983, but still comprised only 2.1 percent of the 1983 average daily jail population. Tables and graphs are included.