One of 52 theoretical papers on school crime and its relation to poverty, this chapter focuses solely on changes in student crimes in the period from 1950 to 1975. A number of observations are made about student violence. First, assaults against teachers have increased sharply in the past 25 years in absolute numbers, but not in the percent of teachers assaulted. Further, "assault" is so loosely defined that no clear picture of changes in the intensity of assaults can be developed. Second, fires in schools represent the single most costly act students can perpetrate; costs from fires are increasing more rapidly than the value of all school property. Third, vandalism probably increased in this country up to the early 1970s, and has declined since that time in both cost and frequency, but may have increased in intensity. Fourth, estimates of the costs of crimes occurring in schools varies widely, depending on the group collecting the information and the methodology used for computing the figures. The paper concludes with discussions of probable future actions of pupils, of local schools, and of school security offices. (Author/MLF)