5  Case study 5

5.1 Case study on school shootings

Photograph of students protest for gun law reform.

Students from Miguel Contreras Learning Center High School in Los Angeles demonstrate in front of City Hall after walking out of school to protest U.S. gun violence on May 31, 2022. Photo by Lucy Nicholson, Reuters Source: https://calmatters.org/newsletters/whatmatters/2022/07/mass-shooting-california-gun-laws/

School shootings occur more often in the US than any other country (Mosechkin and Krukovskiy (2019)). The K-12 School Shooting Database (Riedman (2022)) contains data on every instance a gun is brandished, is fired, or a bullet hits K-12 school property. Recently, Hilaire et al. (2022) used this data source to investigate the relationship between perpetrators’ race and how shootings are reported by the media. They found that there were differences by race in the characteristics of school shootings and media reporting of school shootings. Reeping et al. (2022) found that more permissive firearm laws and higher rates of gun ownership were associated with higher rates of school shootings. The latest raw data (Jan 1970-Nov 2022) was provided by the founder and maintainer of the K-12 School Shooting Database, David Riedman. Using this data, we explore whether the level of media coverage of the incident (Local, Regional, or National) differs across age groups and examine if the number of victims is associated with the type of weapon(s) used.

In all, the data consist of 46 variables. The variables included:

  • School_Level: education-level of the school attacked as (1) high school, (2) junior high school, (3) middle school, (4) elementary school, (5) other.
  • Year: year
  • Month: month
  • Number_Victims: Number of victims killed or wounded
  • Media_Attention: Highest level of media coverage (local, regional, or national)
  • Time_Period: Time period in which the incident occurred (After school, Afternoon classes, … , Sport Event)
  • agegroup: Age of the shooter (child, teen, adult)
  • State: State where the incident occurred.
  • Weapon_Type: Type of weapon used in the incident.

The reader is referred to K-12 School Shooting Database data methodology page for more details regarding variables in the data set.

The data are shown in table below.

Summary of findings

Numerical and graphical summaries of the relevant variables are provided below:

(a) Violin boxplot
Figure 5.1: Graphically summary
Table 5.1: Top table: Distribution of the ‘Media Attention’ levels. Bottom table: The distribution of ‘Media Attention’ conditional on the levels of ‘Age Group’.
Table 5.2: A comparison of the median and interquartile range of the number victims under each weapon type used by the shooter. Only data in which the weapon was known was used.
Weapon_Type Median IQR
Handgun 1.0 1.0
Multiple Handguns 1.5 3.0
Multiple Rifles 3.5 5.0
Other 0.0 1.0
Rifle 1.0 2.5
Shotgun 1.0 3.0

The violin plots suggest differences in victim counts by weapon category, with more extreme observations for rifles and shotguns. These graphs describe the data. A suitable statistical test would be needed to assess the evidence of a difference.

Scope of inference

This observational case study describes relationships among the variables in the recorded incidents. It does not establish cause and effect. Whether the findings apply more broadly depends on how complete the database is and how incidents were identified and recorded.

Hilaire, Breahannah, Laurie O Campbell, Viki P Kelchner, Eric D Laguardia, and Cassandra Howard. 2022. “Not Another School Shooting: Media, Race, and Gun Violence in k-12 Schools.” Education and Urban Society, 00131245221092739.
Mosechkin, Ilya N, and Vladimir Y Krukovskiy. 2019. “Victimological Measures for Preventing School Shootings: Expert View.” International Journal of Criminal Justice Sciences 14 (2): 256–66.
Reeping, Paul M, Louis Klarevas, Sonali Rajan, et al. 2022. “State Firearm Laws, Gun Ownership, and k-12 School Shootings: Implications for School Safety.” Journal of School Violence 21 (2): 132–46.
Riedman, David. 2022. K-12 School Shooting Database. https://k12ssdb.org.