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16.170 - Automatic License Plate Readers

Effective Date: 02/01/2019


This policy applies to the use of automatic license plate readers (ALPR) by all Department employees.

This policy defines a minimum set of binding guidelines to govern the use of ALPR data, to enable the collection and use of such data in a manner consistent with respect for individuals’ privacy and civil liberties. 

ALPR uses high speed cameras to photograph vehicle license plates.  ALPR technology will only be placed on law enforcement and parking enforcement vehicles for authorized law enforcement and public safety purposes as set forth in this policy. 

ALPR data is law enforcement information and will be used solely for law enforcement purposes. Any non-law enforcement usage of ALPR data is strictly prohibited.

Any data obtained from ALPR technology will be used and handled pursuant to this policy and applicable city, state, and federal laws. A search warrant will be obtained when legally required. 

16.170-POL - 1 Definitions

ALPR Administrator: A trained Department employee who manages the utilization of the ALPR software from the end user through training, reporting and monitoring. The PEO and Patrol ALPR Administrators work closely with Seattle ITD staff versed in the ALPR system.

The Department will have two ALPR Administrators: one for Parking Enforcement personnel who use Autovu, and one for personnel who use the Back Office System Software (BOSS).

Autovu data is used during a PEO’s shift and is not retained at the completion of their shift.  BOSS retains data for 90 days.

Automated License Plate Reader (ALPR): A device that uses cameras and computer technology to compare digital images of license plates to lists of known plates of interest.

Back Office System Software (BOSS): ALPR network data storage system accessible only to trained and authorized Department employees. The BOSS software resides on the BOSS server.

Hit: Alert from the ALPR system that a scanned license plate number may be in the NCIC or other law enforcement database for a specific reason including, but not limited to, being related to a stolen vehicle, wanted person, missing person, domestic violence protective order, other criminal activity, or parking violation.

Hot List: License plate(s) associated with vehicles of interest from an associated database, including, but not limited to: National Crime Information Center (NCIC), Washington Crime Information Center (WACIC) and Department of Licensing (DOL) databases, and local Be on the Lookout notices (BOLOs).

Reads: Data obtained by an ALPR of license plates within public view that were read by the device, including images of the plate and vehicle on which it was displayed, and information regarding the location of the police vehicle at the time of the ALPR read.

SCOFFLAW: License plate associated with four or more unpaid parking citations subject to City Scofflaw Ordinance, SMC 11.35.

16.170-POL – 2 General Policy

1. Only Employees Trained in the Use of ALPR Equipment Will Use and Access ALPR Devices and Data

Before employees operate the ALPR system or access ALPR data, they will complete Department training on the proper and lawful use of the system.

2. The Education and Training Section Will Coordinate with the Two Department ALPR Administrators to Provide Department ALPR Training and Document Approved Users

Training will include:

- Instruction on the appropriate use and collection of ALPR data with emphasis on the requirement to document the reason for any data inquiry in BOSS, whether through the BOSS client or the BOSS server.

- Requirements of any Surveillance Impact Report regarding ALPR adopted by the City Council.

Additionally, all ALPR Operators will maintain ACCESS Level 1 Certification pursuant to ACCESS WACIC and NCIC.

The Education and Training Section will coordinate with the two ALPR Administrators to maintain a roster of approved ALPR users.

- The Parking Enforcement ALPR Administrator will maintain a list of all employees trained in the use of Parking Enforcement ALPR equipment.

- The Patrol ALPR Administrator will maintain a list of all employees trained in the use of Patrol ALPR equipment and the BOSS client software.

3. Authorized and Prohibited Uses

ALPR systems will only be deployed for official law enforcement purposes. These deployments are limited to:

- Locating stolen vehicles;

- Locating stolen license plates;

- Locating wanted, endangered or missing persons; or those violating protection orders;

- Canvassing the area around a crime scene;

- Locating vehicles under SCOFFLAW; and

- Electronically chalking vehicles for parking enforcement purposes.

ALPR data maintained on BOSS will only be accessed by trained, SPD employees for official law enforcement purposes. This access is limited to:

- Search of specific or partial plate(s) and/or vehicle identifiers as related to:

- A crime in-progress;

- A search of a specific area as it relates to a crime in-progress; 

- A criminal investigation; or

- A search for a wanted person; or

-Community caretaking functions such as, locating an endangered or missing person.

- Officers/detectives conducting searches in the system will complete the Read Query screen documenting the justification for the search and applicable case number.

ALPR will not be used to intentionally capture images in private area or areas where a reasonable expectation of privacy exists, nor shall it be used to harass, intimidate or discriminate against any individual or group.

3. ALPR Operators Will Respond to Hits/Alerts by Confirming the ALPR Information

When an operator receives a Hit/alert indicating a positive Hit from the Hotlist database, a digital image of the license plate will be displayed on the mobile data computer screen.

- ALPR operators will compare the digital image of the license plate to the Hotlist information to verify the Hit for both the state and characters on the plate.

- ALPR operators will confirm the ALPR information by radio or Mobile Data Computer (MDC) to immediately confirm the Hit prior to taking enforcement or other type of police action (absent exigent circumstances).

- ALPR operators will enter a disposition for all ALPR Hits by selecting either "Accept" or "Misread" before removing the Hit from the computer screen.

Dispositions include:

- Stolen Recovery – Arrest;

- Stolen Recovery – No Arrest;

- Eluded – Lost;

- Plates only;

- SCOFLAW; and

- Wanted person or vehicle Misread/Twin plate

- Positive ALPR hits leading to action requiring an incident report will be documented within the report narrative.

16.170-POL – 3 ALPR Equipment

1. ALPR Operators Will Ensure ALPR Cameras Are Properly Affixed to the Assigned Police Vehicle Prior to the Start of Their Shift

Operators will inspect cameras for damage or excessive wear.

2. Operators Will Notify the ALPR Administrator Upon Discovery of any Damaged or Inoperable ALPR Equipment

Operators will document the damage/issue on the Vehicle Damage Report form 1_35 found in Word Templates.

3. Operators Will Activate the ALPR Software and Receive the Automatic Updated Hot List at the Start of Each Shift

ALPR units installed on marked patrol and PEO vehicles will be activated and used at all times unless the operator of the vehicle has not been trained.

4. Operators Will Ensure that the ALPR System is Operational by Confirming all Three Cameras and GPS are Functioning Properly at the Beginning of Their Shift

Operators will alert Seattle ITD and the ALPR administrator of any equipment defects.

5. Operators Will Upload, Their ALPR Data Accumulated from Their Shift to the BOSS Server Prior to Shutting Down Their Computer

16.170-POL – 4 ALPR Administrator Roles and Responsibilities

1. The Parking Enforcement Unit Will Assign and Support a Parking Enforcement ALPR Administrator for ALPR Electronic Vehicle Chalking

PEOs may use ALPR electronic vehicle chalking to assist in enforcing parking restrictions in time-limited, no pay parking zones and electronic parking permit management in restricted parking zones (RPZ).

PEOs will not have access to stored ALPR data in BOSS.

2. Technical and Electronic Support Unit (TESU) Will Assign and Support the Patrol ALPR System and Parking Enforcement Vehicles used for Scofflaw Enforcement

3.  The ALPR Administrators Will Update Access for Approved, Trained Users

4. The ALPR Administrators Will Assist the Office of Inspector General in Conducting Periodic Audits of the Department’s ALPR Systems

16.170 POL- 5 ALPR Data Storage and Retention

ALPR technology collects digital images of license plates and associated license plate numbers.  The technology collects the date and time that the license plate passes a digital-image site where an ALPR is located.  The Department will store ALPR data in a secured law enforcement facility with multiple layers of security protection. Firewalls, authentication and other reasonable security measures will be utilized.  Only trained Department employees can access stored ALPR data and all data search requests are logged within the system. 

1. Except for Hits and Data Used for a Parking Enforcement Action, No Data Collected by Parking Enforcement ALPR Used for Electronic Vehicle Chalking to Enforce Parking Restrictions in Time-Limited, No Pay Parking Zones and Electronic Parking Permit Management in RPZs will be Accessed after the Shift in which it was Collected

Metadata and images of detections will be deleted from the server within 24 hours of collection.

2. TESU Maintains Operational Control Over Patrol ALPR and ALPR Used for Scofflaw Enforcement

3. The Department Will Store Read Data from Patrol ALPR and ALPR Used for Scofflaw Enforcement for 90 days on the BOSS Server

After the 90-day retention period, the BOSS server will purge the data unless it has become, or it is reasonable to believe it will become, evidence in a criminal or civil action, or is subject to a lawful action to produce records.  In those circumstances the applicable data should be downloaded from the BOSS server onto portable media and entered into evidence.

4. ALPR Data Related to a Criminal Investigation Will be Retained by the Case Detective in the Investigation Case File for a Period of Time in Accordance with State Retention Laws

16.170 POL-6 Stored Read Data from Patrol ALPR and ALPR Used for Scofflaw Enforcement Access and Use

1. Employees Accessing ALPR Data Must Login Through the ALPR Password-Protected System

This system records when an employee accesses ALPR data by logging the employee’s name, the date and the time of the request.

2. Employees Conducting Searches in the ALPR System Will Provide a Case Number and Justification for the Search

If a case number does not exist, the employees will provide thorough justification for the legitimacy and lawful purpose of the search.

3. Employees Will Not Share ALPR Passwords and Login Credentials

16.170 POL-7 Releasing or Sharing ALPR Data

ALPR data will only be shared with other law enforcement or prosecutorial agencies for official law enforcement purposes or as otherwise permitted by law.

Requests for ALPR data by non-law enforcement or non-prosecutorial agencies will be processed by the Legal Unit pursuant to the applicable Rules of Civil or Criminal Discovery or the Washington Public Records Act, Chapt. 42.56 RCW. The Legal Unit will maintain requests for ALPR data by non-law enforcement or non-prosecutorial agencies.

The Office of the Inspector General may audit Department records at any time to ensure compliance with this policy.



Adrian Diaz, Chief of Police
Address: 610 5th Avenue, Seattle, WA, 98104-1900
Mailing Address: PO Box 34986, Seattle, WA, 98124-4986
Phone: (206) 625-5011
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