Spatial Analysis of Crime Point Data in ArcGIS Pro

Rev. 9 March 2025

Spatial analysis consists of "methods to study the location, distribution, and relationship of spatial phenomena" (Bäing 2014).

Because geospatial data is fundamentally quantitative, these methods are often based in complex statistics that can be impenetrable to most GIS users. However, the fundamental ideas behind these methods are often conceptually straightforward, and the implementation of the algorithms in software means that most GIS users only need to have a general understanding of the capabilities and limitations of these methods in order to be able to use them effectively.

This module demonstrate some spatial analysis methods that can be used with point data in ArcGIS Pro. While this tutorial uses Chicago crime data as an example, these techniques can be applicable to any data consisting of points for a single type of phenomenon.

Crime Data Limitations

Some major cities make georeferenced crime location data available for analysis through their open data portals. This data has a number of limitations that you should be aware of as you perform your analysis:

Acquire and Process the Data

Crime Data

The Chicago Police Department (CPD) provides a dataset of reported incidents of crime (with the exception of murders where data exists for each victim) that occurred in the City of Chicago since 2001. This dataset is made available through a dashboard and web map for convenient online analysis, and is also made available as raw CSV point data that can be imported into GIS. The original source of the data is the Chicago Police Department's CLEAR (Citizen Law Enforcement Analysis and Reporting) system.

The Chicago data portal uses the Socrata web app, which permits download of the data as CSV files with columns of latitude and longitude.

The app also provides a facility for filtering data. Because this data a variety of crimes over more than 20 years, downloading the millions of points and 1.6 gigabytes of data will result in data that will be very slow to analyze with ArcGIS Pro.

Therefore, in this example, we use filters to download separate Robbery data files for the years of 2019 and 2023.

Point data in CSV files with longitudes and latitudes can be imported into ArcGIS Pro and stored in the project database.

  1. Create a new project and a new map.
  2. Download a CSV file of crime data from the Chicago Data Portal, filtered to show only the desired crime Primary Type (Robbery) and Year (2019) and save it to a meaningful file name (Crime_2019).
  3. Repeat for a later period (2023) and save to a separate file (Crime_2023).
  4. Under Analysis, Tools, open the XY Table To Point tool to import the points into the project geodatabase.
  5. Repeat with the 2023 data.
  6. Symbolize with semitransparent hollow circles (80% transparency and multiply blending) so you can see point clusters.
Downloading 2019 and 2023 Chicago crime data from the Chicago Data Portal and importing it into a project geodatabase

Viewing Attributes

View the Attribute Table to find the count of features and the different available attributes.

You can get statistical summaries of columns by selecting Explore Statistics.

Viewing statistics in the attribute table

Neighborhood Areas

While neighborhoods are vernacular areas that often have unclear and contested boundaries, cities commonly create data files for neighborhoods that define unofficial boundaries that are useful for reference and context.

Note that neighborhoods are used in this tutorial for aggregating crime points rather than census tracts because the larger neighborhood areas mitigate the small numbers problem that would be more common with smaller tract areas and often sparse crime location data.

The City of Chicago makes neighborhood boundaries available as shapefiles that can be downloaded, unzipped, and imported into ArcGIS Pro.

Acquiring a neighborhood boundary feature class

Census Tracts

For this example, we get demographic data for census tracts from the the US Census Bureau's 2019-2023 American Community Survey five year estimates.

Census tracts are organizational boundaries used for USCB data collection that are drawn to roughly align with neighborhood borders and, ideally, contain 4,000 residents, although the number of residents can vary depending on local characteristics (USCB 2019).

For convenience, we will use the tracts layer from the Minn 2019-2023 ACS feature service from the University of Illinois ArcGIS online organization.

Downloading and importing census tract demographics

Analyze the Data

ModelBuilder

ModelBuilder is a visual programming language in ArcGIS Pro that allows you use a graphical editor to create custom tools that allow you to automate complex, tedious, or repetitive tasks where there are consistent step-by-step workflow sequences of operations.

Using ModelBuilder, you graphically chain together sequences of tools from the toolbox. This will be useful for this example because you will be executing a long sequence of tools, and using them in a ModelBuilder diagram will both make it easier to keep track of what you are doing and will allow you to easily rerun the analysis if you need to modify or fix one step in the analysis.

A ModelBuilder diagram

To start a new ModelBuilder diagram, on the Analysis ribbon, select ModelBuilder.

Creating a ModelBuilder diagram

Save ModelBuilder

You should periodically save your ModelBuilder diagrams from the ModelBuilder ribbon as you work on your project.

Saving a ModelBuilder diagram

Neighborhood Demographics

Demographics are "the statistical characteristics of human populations (such as age or income)" (Merriam-Webster 2024).

To analyze the relationship of crime to community characteristics, we need demographic data for the neighborhoods.

The neighborhood data from the City of Chicago contains only boundaries, so we will have to use a spatial join to summarize census tract demographics within neighborhoods.

A spatial join is a join where data from a join data set is copied into a target data set based on proximity of features in the two data sets.

Figure
Spatial joins for attributes

Add the Summarize Within tool to your diagram.

Main map

Small Maps

To create the infographic, we will need to place the different feature classes on separate maps.

  1. Create the rate map.
  2. Create the change map.
  3. Create the hot spot map.
Creating the small maps for the infographic

Small Map Frames and Legends

Add the three small maps to the infographic as map frames with captions.

  1. Small map frames: 2.3 x 3
  2. Remove the border
  3. Add a legend
  4. Add caption text (18 pt Arial)
Small map frames

Correlation Results

Add a correlation x/y scatter chart to your Rate_2023 map with the crime rate on the y-axis and a derived demographic variable you think might be correlated with that rate on the x-axis (Percent_Foreign_Born).

Click on the rate map frame to make it the active map and add a chart frame for the scatter chart to your layout.

X/Y scatter chart

Export PDF

Export PDF