A Shot in the Dark: Analyzing Mass Shootings in the United States, 2014-2019

By: Miranda Ramnarayan

Geovis Project Assignment @RyersonGeo, SA8905, Fall 2019

The data gathered for this project was downloaded from the Gun Violence Archive (https://www.gunviolencearchive.org/), which is a non-for Profit Corporation. The other dataset is the political affiliation per state, gathered by scrapping this information from (https://www.usa.gov/election-results). Since both of these datasets contain a “State Name” column, an inner join will be conducted to allow the two datasets to “talk” to each other.

The first step is importing your excel files, and setting up that inner join.

There are four main components this dashboard is made of: States with Mass Shootings, States with Highest Death Count, Total Individuals Injured from Mass Shootings and a scattergram displaying the amount of individuals injured and killed. All of these components were created in Tableau Worksheets and then combined on a Dashboard upon completion. The following are steps on how to re-create each Worksheet. 

1. States with Mass Shootings

In order to create a map in Tableau, very basic geographic information is needed. In this case, drag and drop the “State” attribute under the “Dimensions” column into the empty frame. This will be the result:

In order to change the symbology from dots to polygons, select “Map” under the Marks section.

To assign the states with their correct political affiliation, simply drag and drop the associated year you want into the “Colour” box under Marks.

This map is displaying the states that have had mass shootings within them, from 2014 to 2019. In order to automatic this, simply drag and drop the “Incident Date” attribute under Pages. The custom date page has been selected as “Month / Year” since the data set is so large.

This map is now complete and when you press the play button displayed in the right side of this window, the map will change as it only displays states that have mass shootings within them for that month and year.

2. States with Highest Death Count

This is an automated chart that shows the Democratic and Republican state that has the highest amount of individuals killed from mass shootings, as the map with mass shootings above it runs through its time series. Dragging and dropping “State” into the Text box under Marks will display all the states within the data set. Dragging and dropping the desired year into Colour under Marks will assign each state with its political party.

 In order for this worksheet to display the state with the highest kill count, the following calculations have to be made once you drag and drop the “# Killed” from Measures into Marks.

To link this count to each state, filter “State” to only display the one that has the maximum count for those killed.

This will automatically place “State” under Filters.

Drag and drop “Incident Date” into Pages and set the filter to Month / Year, matching the format from section 1.

Format your title and font size. The result will look like:

3. Total Individuals Injured from Mass Shootings

In terms of behind the scenes editing, this graph is the easiest to replicate.

Making sure that “State Name” is above “2016” in this frame is very important, since this is telling Tableau to display each state individually in the bar graph, per year.

4. Scattergram

This graph displays the amount of individuals killed and injured per month / year. This graph is linked to section 1 and section 2, since the “Incident Date” under Pages is set to the same format. Dragging and dropping “SUM (#Killed)” into Rows and SUM (#Injured) into Columns will set the structure for the graph.

In order for the dot to display the sum of individuals killed and injured, drag and drop “# Killed” into Filter and the following prompt will appear. Select “Sum” and repeat this process for “# Injured”.

Drag and drop “Incident Date” and format the date to match Section 1 and 2. This will be your output.

Dashboard Assembly

This is where Tableau allows you to be as customizable as you want. Launching a new Dashboard frame will allow you to drag and drop your worksheets into the frame. Borders, images and text boxes can be added at this point. From here, you can re-arrange/resize and adjust your inserted workbooks to make sure formatting is to your desire.  

Right clicking on the map on the dashboard and selecting “Highlight” will enable an interactive feature on the dashboard. In this case, users will be able to select a state of interest, and it will highlight that state across all workbooks on your dashboard. This will also highlight the selected state on the map, “muting” other states and only displaying that state when it fits the requirements based on the calculations set up prior.

Since all the Pages were all set to “Month/Year”, once you press “play” on the States with Mass Shootings map, the rest of the dashboard will adjust to display the filtered information.

It should be noted that Tableau does not allow the user to change the projection of any maps produced, resulting in a lack of projection customization. The final dashboard looks like this: