The persistent belief that some relationship exists between marihuana use and crime is not without statistical support. Undoubtedly, the marihuana user of the 1920's and 1930's was overrepresented in the nation's jails and penitentiaries and in the general crime and delinquency statistics. Especially during the late 1920's and early 1930's when the nation was preoccupied with lawlessness, the translation of this statistical correlation into a causal hypothesis is not surprising.

The increasing incidence of use in the mid-sixties by white, affluent, middle class, high school youth, college students and adults has occasioned a reevaluation of the marihuana user and a reexamination of the crime issue. The overwhelming majority of the new marihuana offenders have had no previous arrests, and come from the normally low risk, middle and upper socioeconomic population groups.

Recent public opinion surveys suggest that considerable social disapproval is attached to the "hippie" life style, unconventional mode of dress and apparent disregard for the law displayed by many of these individuals. Nonetheless, fewer persons are now willing to classify as criminal those marihuana users whose only contact with the law has been as a result of their marihuana use. Perceptions have undergone a change as a result of the increased usage of marihuana among youth of the dominant social class. Nonetheless, a statistical association remains.

First, the majority of both marihuana users and offenders other than actual marihuana law violators fall into the 14-to-25-year age group. Second, the majority of those arrested for marihuana law violations as well as other delinquent or criminal acts were, and to a much lesser degree, still are, drawn from the same "high risk" populations, such as minority groups, socially and economically disadvantaged, young, male, inner-city residents.

Third, various offender populations subjected to study often included a number of marihuana users, although it was not the marihuana violations per se but other, more serious criminal conduct that originally brought most of them to the attention of the authorities. Finally, during the past five years, marihuana law violators have increasingly swelled the crime and delinquency statistics; in most cases, their only contact with the law has been for these marihuanaspecific offenses.

The Philadelphia study corroborated this continuing statistical association. The simple relationship between using marihuana and committing offenses was positive and statistically significant, and there was also a high correlation between frequency of smoking marihuana and committing offenses. These direct associations were reduced to insignificance, however, upon further analysis of the data, and other explanations for the coincidence of marihuana use and crime became evident. These included: race, education, age, the use of other drugs, and having drug-using friends.

We conclude that some users commit crimes more frequently than non-users not because they use marihuana but because they happen to be the kinds of people who would be expected to have a higher crime rate, wholly apart from the use of marihuana. In most cases, the differences in crime rate between users and non-users are dependent not on marihuana use per se but on these other factors.

In summary, although the available evidence suggests that marihuana use may be statistically correlated with the incidence of crime and delinquency, when examined in isolation from the other variables, no valid evidence was found to support the thesis that marihuana' by itself, either inevitably, generally or even frequently causes or precipitates the commission of crime, including acts of violence, or juvenile delinquency.

Within this framework, neither the marihuana user nor the drug itself can be said to constitute a danger to public safety. For, as two researchers have so cogently stated for the Commission, "Whatever an individual is, in all of his cultural, social and psychological complexity, is not going to vanish in a puff of marihuana smoke."