US Mass Shooting 1: Overview Analysis and Root Cause 1966-2019

myht63
Sep 8, 2020
4 min read

Updated: Sep 22, 2020

By My Ho

Cleaned Dataset link (My Kaggle): click here

Cleaned Dataset link (My Github): click here

The severity of mass shooting/gun violence and its effect on US families has always been a concern in US. To provide readers with more insight of this current affair based on data of typical cases from 1966 to 2019 in all over US regions, this analysis was written for such purpose.

This first analysis will focus mostly on general information and overview visualization of mass shooting/gun violence over time series from 1966 to 2019. For further analysis in other factors such as shooter’s races, gender, behavior, mental health, etc. can be found in suggested link at the end of this analysis writing.

While gun violence is a general term, mass shooting is more specific and which has several different but common definition in US. The Congressional Research Service defines mass shootings, as multiple, firearm, homicide incidents, involving 4 or more victims at one or more locations close to one another. The FBI definition is essentially the same.

Dataset

This analysis data source does not cover every single case that have happened but typical ones, and dataset has been accumulated and cleaned (fixed) from multiple data source to ensure its preciseness and integrity as much as possible. Dataset includes mass shooting cases with total of victims from 4 people and above (including homicide). Data cleaning process is described in separate writing (link).

Another data source that cover most mass shooting cases is GVA (Gun Violence Archive) - a not for profit corporation formed in 2013 to provide free online public access to accurate information about gun-related violence in the United States. However, GVA dataset is limited with data starting from 2014 and does not include factors related to shooter’s race, gender, mental health status, event’s location, motives, etc.

Mass shooting is happening more frequent

Video 1: Mass shooting cases is happening more frequently

In general, mass shooting is getting more frequent every year and areas with higher population seems to have more mass shooting cases occur (Western parts of US, California, Washington). This visualization will be analyzed later with a bigger dataset from GVA. (Figure 1 and video 1, 2 )

Figure 1: Mass shooting total cases in US from 1966 to 2019

Video 2: US Population density 1966-2010

(Source: https://www.youtube.com/watch?v=lbC9-WfuOIw)

Most common incident areas and root cause of mass shooting

Figure 2: Incident areas of mass shooting from 1966-2019

The top 4 incident places areas are as follow in ranking from the most to least common (Figure 2).

- Public areas: many shooters start fire in public places where he/she could kill/injure as many as possible or sometimes it is only about randomly targeting at anyone he/she sees. There is high number of cases where causes are unknown due to shooters got away, killed by police or the shooters take their own life after committed crime. Besides unknown cases, other common causes (from most to lease) are terrorism, psycho, anger, and racism (Figure 3).

Figure 3: Public incident areas with mass shooting causes and shooter’s status

- Home: home could be shooter’s home or victims’ home. Most causes for this incident place is classified as psycho since shooters were killing their own family members and 63% of them committed suicide after that. Still many cases’ causes are unknown due to shooters were dead before police came and since then cases’ cause turned harder to be investigated, or in some cases shooters were someone outside broken into one’s house, shooting people in the house and then got away without being known. Other common causes are domestic dispute and anger with which again more than 50% of shooters turned the gun to themselves after committed crime and died before being arrested. (Figure 4)

Figure 4: Home as incident areas with mass shooting causes and shooter’s status

- School: School is among the third common area for mass shooting with around 60% shooters in age range from 10 to 20 years old, and 79% shooters in age arrange from 10 to 30 years old. Top reasons are terrorism, the others are unknown, anger and frustration with school. (Figure 5)

Figure 5: School as incident areas with mass shooting causes and shooter’s status

- Former workplace: unemployment, anger, revenge, and some other unknown reasons also caused shooter’s former workplace become the 4th most common area for mass shooting issue. Shooters seem too frustrated when it comes to unemployment/reasons related to employment that around 52% of shooters targeted at former workplace killed themselves after committed crime. (Figure 6)

Figure 6: Former workplace as incident areas with mass shooting causes

In total, 25,9% mass shooting’s cause is unknown due to missing data, shooters got away, killed or committed suicide. Other top 8 causes led to mass shooting was psycho, terrorism, anger, frustration, domestic dispute, unemployment, revenge, and racism. Meanwhile shooters with anger, frustration, dispute (emotional control related) mainly targeted at some specific individuals, highest average total victims (both killed and injured) falls for terrorism, unemployment, and racism cases (social issue related). (Figure 7)

Figure 7: Top reasons of mass shooting 1966-2019

This dataset might not cover all mass shooting cases in US but hopefully it its analysis could reflect some common features of current gun violence situation in US. The next analysis will focus more on shooter’s behaviors that fit with some specific features and motives of him/her.