The study found that property crimes were more frequent in 1965 than in 1977; crimes against persons had doubled from 1965 to 1977; muggings and street crimes, formerly insignificant, were frequent in 1977. Furthermore, the 1977 delinquents were more knowledgeable about the criminal process but far less willing to cooperate or assume responsibility for their actions. Females were involved in more types of crimes than before, but still acted primarily as support persons to male accomplices. Female delinquents were less likely to be suspected and treated less severely by authorities. The proportion of non-French juveniles involved in crime increased, reflecting the influx of foreign residents (Maghrebians, Yugoslavs) into the country. Justice responses to juvenile delinquency also intensified, with speedier arrests and more perfunctory adjudications. Juveniles without work and with a prior record are treated more severely; penalties are heavier, frequently involving incarceration; and cultural background appears to affect the type of sentence (e.g., Maghrebians are incarcerated while Gypsies are released to their families). Footnotes and tabular data are given.