ATHERTON POLICE DEPARTMENT
Inter-Department Correspondence
To: Chief McCulley
From: Commander Larsen
Date: March 27', 2025
Subject: 2024 Automated License Plate Reader (ALPR) Program Analysis Report Overview
In November 2019, the Town Council approved the lease of two fixed ALPR cameras, which were installed in January 2020. Since then, the Town's ALPR program has continued to expand.
In 2024, two additional cameras were installed, bringing the total to 50. One more camera is pending installation and is expected to be operational in 2025.
These cameras have been strategically positioned to serve as a critical investigative tool, aiding the Atherton Police Department in crime prevention and resolution. ALPR cameras function as a pointer system, assisting law enforcement in identifying vehicles connected to suspects, witnesses, or victims. Additionally, they help develop exculpatory information that refines investigative efforts. The system captures and stores images of vehicles, scanned license plates, and the locations where the images were taken, with data retention limited to a rolling 30-day period.
Plate Read Summary
The Flock ALPR system retains data for a rolling 30-day period. Between February 25 and March 24, 2024, a total of 3,776,204 license plate reads were recorded in Atherton. If this figure is used as a monthly average, the estimated annual total would be approximately 45,314,448 plate reads.
Total Vehicle Volume Total Unique Vehicle Volume
3,776,204 1,548,260
Total Vehicle Volume
Breakdown
#Atherton CA PD
150K
120k
Mar 8, 2025 we 15, 2025 Mer 17, 2025 Ma: 23, 2025 Mar 24, 2015 Holbrook Palmer Park Data
During the same period (February 25-March 24, 2024), the ALPR cameras at the entrance of Holbrook Palmer Park recorded 12,368 license plate reads. Based on this monthly average, the projected annual total for the park's entrance is approximately 148,216 plate reads.
Total Vehicle Volume Total Unique Vehicle Volume
12,368 3,071
Total Vehicle Volume
•Atherton CA PD
600
500
200
Feb 25,2023 Feb 28,3023 FeD 27, 3023 res 28, 202s Mr 1, 3025 Mar 2, 2023 Mer 4, 2025 Mar s, aors Mar 9. 3023 Mar 10, 2025 Mr T1,202S Mer 12, 3025 Mar 12, 3025 Mar 14, 2023 Mer 18, 3028 ser 17,3028 Mar 18, 3073 Mer 19, 2023 Mar 20, 20281 Mr 22, 3025 Mor 23, 2025 Mar 24, 3028 ALPR Alerts
In the 2024 calendar year, the ALPR system generated 204 alerts in Atherton. An ALPR alert notifies law enforcement of flagged vehicles, including stolen vehicles, Amber Alerts, wanted persons, or subjects under investigation. Alerts for stolen license plates were disabled due to a high volume of false alerts.
System Queries
Atherton Police Department personnel conducted 1,865 search queries within the ALPR system in 2024. These searches were part of investigations related to burglary, theft, vandalism, robbery, vehicle code violations, suspicious vehicles, suspicious circumstances, and missing persons cases.
Success Stories
Four stolen vehicles and one set of stolen license plates were recovered due to ALPR activations.
• The system assisted in identifying suspects involved in two burglaries, both of which are under active investigation.
• The ALPR system played a crucial role in resolving a reported kidnapping case. A witness observed a teenager being pulled into a vehicle and provided a description to investigators. Using ALPR data, authorities quickly identified the vehicle's license plate and contacted its registered owner. It was determined that the vehicle belonged to a transportation service for children with special needs. Thanks to the ALPR system, the case was resolved in approximately five minutes—-saving investigators several hours of work.
System Challenges
• ALPR data is only retained for 30 days, limiting the ability to retrieve information for long-term investigations. If a crime is reported more than 30 days after it occurs, related ALPR data is no longer accessible.
Camera Locations
Fixed ALPR Camera Locations:
1. Holbrook Palmer Park Entrance
2. Holbrook Palmer Park Exit
3. Northbound Middlefield Road at Ravenswood Avenue
4. Eastbound Watkins Avenue at El Camino Real
5. Westbound Fair Oaks Avenue at Middlefield Road
6. Southbound Middlefield Road at Jennings Lane
7. Northbound Alameda De Las Pulgas at Walsh Road
8. Northbound Frederick Avenue at Ringwood Avenue
9. Westbound Selby Lane at Oakwood Boulevard
10. Westbound Alejandra Avenue at El Camino Real
11. Westbound Valparaiso Avenue at El Camino Real
12. Northbound Camino Por Los Arboles at Valparaiso Avenue
13. Eastbound Atherton Avenue at Alameda De Las Pulgas
14. Westbound Atherton Avenue at El Camino Real
15. Westbound Selby Lane at El Camino Real
16. Eastbound Selby Lane at West Selby Lane
17. Eastbound Camino Al Lago at Alameda De Las Pulgas
18. Westbound Isabella Avenue at El Camino Real
19. Glenwood Avenue at Laurel
20. Westbound Marsh Road at Middlefield Road
21. Eastbound Stockbridge Avenue at Alameda De Las Pulgas Privately Funded ALPR Camera Locations:
22. Eastbound Britton at Alejandra Avenue
23. Eastbound Emilie Avenue at Park Lane
24. Westbound Alejandra Avenue at Brittany Meadows
25. Westbound Winchester Drive at El Camino Real
26. Eastbound MacBain Avenue at Emilie Avenue
27. Inbound James Avenue
28. Inbound Linden Avenue
29. Eastbound Oak Grove at Manzanita
30. Westbound Oak Grove at Encino Road
31. Northbound Lloyden Drive at Fair Oaks Lane
32. Eastbound Lloyden Drive at El Camino Real
33. Eastbound Wilburn Avenue at El Camino Real
34. Westbound Alejandra Avenue at Brittany Meadows
35. Westbound Stockbridge Avenue at El Camino Real
36. Westbound Almendral Avenue at El Camino Real
37. Westbound Tuscaloosa Avenue at El Camino Real
38. Westbound Fletcher Drive at Alameda De Las Pulgas
39. Westbound Walsh Road at Alameda De Las Pulgas
40. Westbound Atherton Avenue at Alameda De Las Pulgas
41. Southbound Alameda De Las Pulgas at Stockbridge Avenue
42. Eastbound Polhemus Avenue at Alameda De Las Pulgas
43. Northbound Elena Avenue at Valparaiso Avenue
44. Northbound Santiago Avenue at Valparaiso Avenue
45. Northbound El Camino Real at Walnut Avenue, Lanes 1-2
46. Northbound El Camino Real at Walnut Avenue, Lanes 2-3
47. Southbound El Camino Real at Selby Lane, Lanes 1-2
48. Southbound El Camino Real at Selby Lane, Lanes 2-3
49. Westbound Reservoir Road at Walsh Road
50. Westbound Sargent Lane at Reservoir Road
51. Walsh Road area (installation planned for 2025)
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Conclusion
The ALPR program in Atherton has proven to be a valuable tool for law enforcement, aiding in crime detection, suspect identification, and rapid response to critical incidents. The system's effectiveness is evident in the successful recovery of stolen vehicles and its role in resolving criminal investigations. However, the 30-day data retention limit presents challenges for long- term investigations. Continued assessment and potential system enhancements may further improve its effectiveness in supporting public safety.