question of what the relationship might actually be between the form of lethal school violence that was concentrated in inner-city schools and the seemingly newer form of lethal school violence that erupted in suburban schools in the late 1990s. Several such relationships were possible. One was that the different forms of violence were the products of similar causes that played out differently in the different community contexts. A second was that the inner-city violence had created the conditions that shaped the later suburban violence. A third possibility was that there was, in fact, little relationship between the urban violence and these new cases.
The decision to take up the scientific issue of whether this was a new and unique form of lethal school violence had important implications for case selection. It would be important to look closely at examples of lethal school violence in inner cities to determine whether the causes of such violence were similar to the causes of the newer forms of violence. In effect, we could choose the cases to get some variation on the dependent variable: within the class of incidents neutrally described as lethal school violence, we could look at the form that this violence took in different kinds of communities—urban, suburban, and rural. If it turned out that the antecedents to lethal school violence in inner-city schools were different from those in suburban and rural schools, then we would have some evidence pointing toward a firmer conclusion that this was a separate strain of violence.
But there was another reason to look at lethal violence in inner-city schools. A preliminary look at the data indicated that levels of overall lethal violence in inner-city schools were much higher than in suburban-rural schools and had been that way for a long period of time. By developing cases on lethal violence in inner-city schools and comparing them with lethal violence in suburban-rural schools, we could put these incidents under a microscope and describe the structure of the similarities and differences in the character and antecedent causes of lethal violence in different settings. This would help us understand whether there was something about inner-city communities that made them immune to the forms of violence that hit suburban-rural schools in the late 1990s, and whether there was something about the suburban and rural communities that seemed to protect them from the violence that struck the inner cities in the decade from 1985 to 1995.
These considerations were sufficient to persuade the committee that a portion of our limited resources should be focused on developing cases of lethal violence in inner-city schools. To find such cases, we simply had to relax the time frame under consideration. In the period 1990–1992, we found two inner-city schools that had experienced incidents in which multiple individuals were killed and injured. A school in Chicago experi