Of all sexual assaults, 31 percent involved the most serious types of offenses--forcible rape, forcible sodomy, or assault with an object. About 93 percent of all sexual assaults were perpetrated by someone known to the victim, while 7 percent were committed by strangers. An offender was arrested in 61 percent of cases, and 91 percent of all sex offenders apprehended were referred to criminal or juvenile court. Sexual assaults occurred most frequently during the summer months, 58 percent occurred in the home of the victim or the offender, and 96 percent were committed by single offenders. Approximately 78 percent of all sexual assault victims were juveniles, and over 70 percent of all victims were 15 years old or younger. Sexual assault victims were primarily women and primarily white. The average age of a sex offender was 24 years, 9 years older than the average victim, and 92 percent of all sex offenders were males. Offender race was white in 74 percent of sexual assaults, while 23 percent involved black offenders. Of all sexual assaults, 20 percent involved forcible rape, 8 percent involved forcible sodomy, 3 percent involved sexual assault with an object, 46 percent involved forcible fondling, and 22 percent involved statutory rape. Less than 1 percent of all sexual assault offenses were cases of ejaculation or excretion upon the victim. Detailed statistics are provided on the number and nature of sexual assaults. Appendixes contain information on data collection techniques, Wisconsin sexual assault statutes, and the sexual assault data collection form. 10 tables and 7 graphs