Demographic, developmental, and criminal justice variables (the size and level of expenditures of police forces) have particularly significant effects on petty and property crimes. The growth of petty and property crimes during this century parallels the growth in population and economic development. Conversely, offenses against persons are related to developmental factors only, and 'good order' offenses are affected by neither demographics nor development. An analysis of structural and technological variables and crime patterns reveals an inverse relationship between crimes and unemployment, weak but positive relationships between offenses against persons and urbanization, a strong positive association between offenses against persons and police force size and between all types of offenses except good order and motor vehicle, and weak relationships between types of offenses and the proportions of various age groups in the population. Crime trends changed direction at various points and were affected by economic variables. For example, the points at which curves for all offenses converge (1907-13, 1930-37, and 1973-76) represent major periods of change in the national economy. Overall, no cyclical pattern was found; fluctuations were associated with changes in socioeconomic environments. A comparison with U.S. data reveals similar findings (except for property crimes). Implications for future research are discussed. Tables and graphs are included; appendixes provide supplementary data, endnotes, and an index.