For each year during this period, about 4 in every 10 criminal victimizations by armed offenders involved strangers. Since 1976, violent crime by unknown offenders with guns was between 13 and 14 percent, except in 1983 when it was 11 percent. About 25 percent of violent crimes by strangers resulted in injury, a percentage that remained relatively stable over time. Assault was the most frequent violent crime, followed by robbery, and rape. Robbery victims who took no self-protective measures were less likely to be injured than those who did. Since 1981, victimization rates for men have decreased more than those for women. Victimization rates for blacks increased up to 1981, then decreased; while that for whites showed little change until decreasing since 1982. Although urban areas had the highest violent crime rates, urban rates have decreased more since 1981 than those in suburban and rural areas. Finally, crime rates for persons under 35 years old rose during the 1970's, while those for older groups remained stable or fell. 3 tables and 8 figures.