Book excerpt: A combination of reprinted articles, most published during the past two years, and original contributions solicited for the anthology, offer a snapshot of the criminal justice understanding of various crimes relating to or involving sex. After a basic overview of sex in the 21st century, they look at nuisance sex behaviors and crime; homosexuality, transvestism, and transsexualism; juvenile sex crimes and behaviors of offenders and victims; dangerous sex crimes; rape; and special issues and concerns.