Chattanooga Police Arrests

The Chattanooga Police Department (CPD) is the primary law enforcement agency for the City of Chattanooga.  Thus CPD is primarily responsible for arrests of individuals for a wide variety of violations of Federal, Tennessee, and Local laws.  In an effort to increase transparency, CPD has made public detailed Arrest data to keep the public informed and provide easy access to research driven institutions.

Data We Use:

  • Arrests- This is a summary level dataset of CPD arrests since January 1, 2018.  Each row in this dataset represents an individual arrested by CPD.  Arrests that have been expunged, related to child abuse, or domestic violence are not included to protect the victims.
  • Arrest Charges- This dataset is a more detailed look at the individual charges levied against a person in an Arrest.  Each row in this dataset represents an individual charge, thus one person arrested on multiple charges will appear multiple times in the data.  Similar to above, charges that have been expunged, related to child abuse, or domestic violence are not included to protect the victims.

Common Arrest Charges

The below graph shows the top 25 individual charges levied against individuals arrested by CPD since January 1, 2018.  Noticeably, the most common arrests seem to be non-Violent other than Assault and Aggravated Assault.  This is in line with Police Incident data which indicates many CPD incidents are non-violent incidents.  The data also supports

Arrest Seasonality

The chart to the right is a pure count of individuals arrested by month.  There is a known seasonality of police incidents and crime overall nationally.  In the warmer summer months, there tends to be higher crime rates, and this is reflected at the arrest level by higher arrests during July-September.  Interestingly, April 2020 was the lowest arrest count on record, which is indicative of the impact of COVID19.

Where Arrests Occur

The below map is a heatmap of where arrests occur.  It should be noted that the arrest data location is anonymized by an appropriate offset to provide some protection to arrested individuals.  Also, the default value the map is filtering by is Traffic Related Arrests since January 1, 2018, but the filter can be changed to suit the users needs.  There may be concentrations of arrests near the Hamilton County jail, 11th Street Police Station, and Amnicola Police Station as these addresses sometimes get used as defaults when there is no available address.  Just looking at the Traffic Related Arrests, there seems to be strong concentration downtown as well as around Hamilton Place Mall. 

Potential Data Follow-Ups and Further Investigation

  • Currently, the two data sets look at individual arrests and individual charges.  It may be beneficial to also create a dataset focused on individuals to see if there are disparities in arrests for individuals.
  • We currently do not include several types of arrests which leads to mismatched summary reporting compared to CPD official arrest numbers.  Potential workarounds may be possible to keep high anonymization of data to allow us to add said data to Arrests and Arrest Charges
For comments and suggestions, please email the Office of Performance Management and Open Data at opendata@chattanooga.gov.