ALPR Reports & Presentations

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The department’s ALPR system has two primary functions. While the ALPR-equipped car is in use, the system compares license plate numbers to one or more existing databases of vehicles of interest to law enforcement agencies, and alerts the officer operating an ALPR-equipped car when a vehicle of interest has been observed. Officers must independently validate that the ALPR system has accurately interpreted the license plate, validate that the license plate matches the vehicle of interest, verify that the alert is valid (e.g. not expired or otherwise deemed invalid), and make an informed decision as to what action to take, if any. The ALPR system refreshes the comparison list every 1-4 hours (depending on vendor) to obtain the most current information. An alert alone does not justify a traffic stop or detention.

The second function serves as an investigative tool for officers and detectives. Since the majority of our investigations are reactive, or after the fact a crime occurs, this tool allows for the investigating officer to check the area of the crime for any potential vehicles that may have been involved, or, having identified a vehicle as being involved, can then use the system to help determine when they have the greatest chance of encountering that vehicle again.

ALPR Operational Status

The Chula Vista Police Department has operated an ALPR system since October of 2007, when the original request to purchase three patrol car mounted ALPR camera systems was publicly proposed at a City Council meeting. The City Council approved that proposal via Council Resolution.

In February 2011, after hearing the public proposal to add a fourth ALPR camera system, City Council approved the purchase via proclamation.

In 2017, due to vendor issues with the existing ALPR camera systems, the Department conducted a search for a new vendor and selected Vigilant Solutions to replace the existing 4 cameras with new equipment and a subscription to the Vigilant ALPR database.

In early 2021, in response to community questions and concerns regarding the ALPR program, the Department implemented a series of changes to the operation of the ALPR system.

Data sharing was limited to only other California law enforcement agencies who must comply with state law (SB54) as it pertains to cooperating with federal law enforcement agencies. Data sharing was discontinued with all federal agencies and fusion centers. The Data sharing list was updated and continues to be posted on the Department’s website.

The department also began preparing quarterly ALPR reports and posting them on the Department’s Website.

In October 2023, City Council unanimously approved the addition of 150 stationary cameras (from Flock Safety) and in March 2024, the installation of these cameras began. Both systems (Vigilant LEARN and Flock Safety) are operational as of March 2024, with Flock Safety's completed deployment of all 150 cameras in April 2024.

Quarterly Reports

Terms & Definitions

In order to assist with understanding the Quarterly ALPR Reports, the following definitions have been provided, listed by slide number.

Slide #2

ALPR Detection/Detection(s): A detection is when the system recognizes a license plate within the field of view of the ALPR cameras (range is out to 12-15 feet from the patrol car), and a photo of that plate is taken and uploaded into the CVPD ALPR database.
Contributor: A contributor is the specific ALPR camera system used by CVPD. There are four systems; all of them are mounted on marked patrol cars.
System: All marked patrol cars are assigned a car number. This is the number of the patrol car the camera system is affixed to.

Slide #3

Hit Detections: A "Hit" occurs when the ALPR system detects a license plate that has previously been identified as a vehicle of interest by law enforcement. These types of vehicles have already been entered into existing and separate law enforcement databases by law enforcement agencies. Common examples of these include stolen license plates, stolen vehicles, missing or wanted persons, and license plates of vehicles suspected on being involved in crime, etc. The Department's ALPR system is set up to compare detections against that database every 45 minutes to ensure the most up to date and accurate information.
- Note: A "Hit" must be verified by the officer prior to taking any enforcement action, such as a traffic stop or detention.
Hot Lists: A hot list is the term that describes the lists of license plates of interest to law enforcement that the ALPR system scans every 45 minutes (as noted under Hit Detections above).

Slide #4

Density Mapping: The green areas show where detections were made. Since the ALPR systems are mounted on patrol cars, they typically tend to be on roads and parking lots. Several factors can contribute to how many detections are made and where:
- Factor #1 = officer assignment. Vehicles in our patrol fleet are not assigned to parts of the city. Vehicles are available for the officers to check out prior to their shift. Often times, we do not have enough cars available and officers on patrol nearing the end of their workday must bring their vehicle back to the station early so that the next group of officers can begin their work shift in the field. Because of this, and the overlapping of certain shifts, is it possible that ALPR cars are unavailable and might not be used at all on a particular shift. This can occur when all three cars were in use on one shift, meaning that none were available for the next.
- Factor #2 = environment. The ALPR cameras have a vision range of approximately 15 feet. Roadways that feature a wide center median – especially with vegetation or other dividing structures – will limit the ability of the ALPR system to capture license plates of vehicles in oncoming lanes.
- Factor #3 = staffing. There are eight police beats on the west side of the city. As the city has grown, we have added beats to the eastern portion of the city and have followed the deployment pattern that has long been established which measures call response and officer availability with the number of calls for service. While there are eight beats west of the I805, there are only four beats east of it. As staffing numbers rise, staffing will increase in the eastern areas accordingly.
- These are 3-month snapshots of detection density. Several factors can affect the volume and location of detection density. When viewed over the course of a year, detections are spread over the entire city's road network.
- To provide context, citizen-initiated call for service heat maps have been included – click here to access. These maps show the location and density of where the community is calling for officers to assist them.

Slide #5

Density Map of Hit Detections: This map shows the locations of the automated Hit Detections (as described under Slide #3).

Slide #6

Detection Browsing: This slide depicts the following…
- ALPR Total Detections: The number of license plates detected and added to the ALPR database by CVPD ALPR cameras only.
- ALPR Total Hit Detections: The number of automated Hit Detections (as described under Slide #3).
- ALPR Density Map Detections: The number of ALPR license plate detections depicted in the map area.
  - Note: The number differs from the first column because the map area shown focuses on the City of Chula Vista and immediately adjacent areas. Detections can occur outside the map area when an ALPR car leaves the city, which happens frequently (common examples include prisoner transports to county facilities, other agency assists, investigations that extend beyond the city boundaries, etc.)
- ALPR Detection Browsing by CVPD Users: The number of searches for vehicles in the ALPR system by CVPD staff during the reporting period.
  - Note: This number indicates only the number of searches conducted, not the number of search results.

2024

2023

2022

2021

Data Sharing Reports

Vigilant LEARN:
Click here to view the current list of all the law enforcement agencies that we share ALPR data with, and who we receive data from. We have restricted data sharing to CA Law Enforcement Agencies only and excluded all Federal Agencies (shown in pages 1-5 of the report). Pages 5-25 show all agencies that share data with us.

Flock Safety:
Click here to access the Transparency Portal.

Past Presentations

Council Meeting – March 23, 2021

Community Forum – April 7, 2021

Council Meeting – April 20, 2021

Technology & Privacy Advisory Task Force – June 2, 2022

Council Meeting – October 17, 2023

City of Chula Vista

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