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License Plate Reader - Standard Operating Procedure






Additionally, a PDF of this document is available for download.


It is the purpose of this policy to provide personnel assigned to the Maryland Coordination and Analysis Center (MCAC) and participating agencies with guidelines and principles for the collection, analysis, dissemination, retention and destruction of information regarding the Automatic License Plate Recognition Operations Center data and facilitating compliance with all applicable laws.


This policy applies to all assigned personnel within MCAC, those working under contract with the MCAC, and to those who use its services (Users).


The Maryland Coordination & Analysis Center will comply with all applicable laws and regulations as they pertain to the collection, use, and dissemination of data obtained through the License Plate Reader (LPR) program. The MCAC will house and maintain the LPR Operations Center System and access to the system will be managed by an LPR Program Administrator.


Primary responsibility for ensuring compliance with the provisions of this policy is assigned to the Executive Director, MCAC. The Executive Director will designate an LPR Program Administrator, who will be responsible for the overall management of the LPR Program.


Automatic License Plate Recognition (ALPR), also known as License Plate Reader (LPR), provides automated detection of license plates. The LPR system consists of a high-speed camera, mounted either at a fixed location or on a mobile patrol vehicle, and a computer to convert data from electronic images of vehicle license plates into a readable format, and then compare the information against specified databases of license plates. The system attaches camera identification, date, time, and location information, to include GPS coordinates, to the digital image and it is maintained electronically in a central location to provide a means of ensuring the license plate number was properly converted. The digital image can include additional information such as:

  • The vehicle's make and model;
  • The vehicle's driver and passengers;
  • Distinguishing features (e.g., bumper stickers, damage);
  • State of registration

If a given plate is listed in the database, the system is capable of providing the vehicle's location, direction of travel, and the type of infraction related to the notification.


Identifying the intended uses of LPR data is critical in assessing any privacy and/or civil liberties implications due to the networking within the MCAC of LPR data collected by participating law enforcement agencies.

The Maryland Coordination and Analysis Center has, as one of its core missions, the sharing of information, thereby assisting law enforcement agencies in the fulfillment of their duties. The MCAC's Operation Center, which is the statewide central repository for license plate reader data, serves specific public safety goals. Specifically, LPR data may be used for, but is not limited to, the following purposes:

  • Crime analysis;
  • To alert law enforcement officials that a license plate number is on a list of targeted license plate numbers (Hot List) or is related to a criminal investigation and is found in the LPR database;
  • To alert law enforcement officials that a license plate number on a hot list has been recorded by a fixed versus mobile camera, possibly requiring notification to law enforcement agencies in proximity or travel route of the identified vehicle;
  • To identify the movement of vehicles operated by individuals currently under an open criminal investigation;


A. Mission

  1. The mission of the Maryland Coordination and Analysis Center is to serve as the focal point for federal, state, local, and private sector partners in the collection, analysis, and dissemination of criminal and homeland security information within Maryland.
  2. In furtherance of that mission, the primary goal of the LPR program is to collect and store vehicle license plate information in an effort to increase the detection of stolen vehicles, stolen tags, wanted and missing persons and aid criminal investigations and prosecutions of other crimes involving vehicles that impact the safety of Maryland's citizens.
  3. The MCAC collects information in a manner consistent with applicable laws, regulations, and internal policies. Collected information is analyzed and distributed in order to provide tactical, operational, and /or strategic intelligence on the existence, identities, and capabilities of criminal suspects or enterprises. In accordance with these principles, LPR data will be queried and disseminated only if there is legal process requiring these actions or there is reasonable suspicion that an individual or enterprise is involved in criminal conduct or activity and the information is relevant to that criminal conduct or activity and the requestor has a legitimate need to know.

B. Data Collection, Retention, and Dissemination

  1. The LPR data collected by the various agencies participating in the LPR program will be transmitted to the MCAC Operations Center via a fiber optic line or through an encrypted Virtual Private Network (VPN). The data will be maintained on the Operation Center server independent of any other law enforcement databases housed at the MCAC.
  2. All LPR system data provided to the MCAC will be stored on the Operations Center server for a period not to exceed one year. After the one year period, the data will be purged unless it has become, or it is reasonable to believe that it will become, evidence, including evidence that tends to inculpate or exculpate a suspect, in a specific criminal or other law enforcement investigation or action. Should data be determined to have evidentiary value, the following paragraph applies:
    1. In those circumstances when data is identified as having evidentiary value, the LPR Program Administrator, or designee, will review the facts of the specific case and determine if the data should be saved. If the LPR Program Administrator determines it is reasonable to believe the data has evidentiary value, the Program Administrator will authorize the transfer of the applicable data from the LPR Program server to a form of digital storage media (CD, DVD, etc.) or other portable storage devices.
    2. Agencies requiring data to be retained by MCAC beyond the established retention period may make a formal request to the MCAC to extend retention. Each request must specify the need for extended retention, the circumstances surrounding the request, the requesting agency's case number, and a specific point of contact within the requesting agency. The MCAC reserves the right to grant or deny agency requests based on the information provided.
  3. The following methods shall be used when disseminating LPR information:
    1. The "need to know" and "right to know", as defined in the MCAC Privacy Protection Policy of a potential recipient must be verified and documented prior to dissemination of LPR information.
    2. Requests for Service (RFS) for License Plate Reader data will be processed in accordance with the MCAC Standard Operating Procedures for Processing Requests for Information and Requests for Service Guidelines.
    3. A Law Enforcement Agency's request to query the LPR data shall be processed provided the agency has a legitimate law enforcement purpose. Mandatory requirements are in place in order to satisfactorily justify the request. These requirements include the purpose of the request, the agency's incident or report number (physical record number), the requestor's name, the requestor's agency and requestor's contact information.
    4. The primary method of dissemination shall be via email, in an electronic format that employs a reasonable level of security to guard against alteration, or fax.
    5. If access to secure email accounts is not practical, the information may be provided to the requestor via digital storage media or paper copy, as determined by MCAC staff.
  4. Reports and other investigative information received and disseminated by the MCAC shall be retained within internal electronic MCAC files. After disseminating LPR information deemed to have evidentiary value, the completed report containing the data will be entered into a searchable database for future exploitation and auditing purposes in accordance with the MCAC Privacy Protection Policy.

C. LPR Operations Center System

  1. The LPR Operations Center system provides the database, query tool, history tracking, and reporting for the LPR program. It manages and provides a storage and search structure for the license plate information being collected in the field. The Operations Center is established as a secure intra-net site within the MCAC IT network, allowing only personnel with password protected access to license plate data collected.
  2. The Operations Center receives data from scanned license plate reads from participating agencies collected via fixed and mobile LPR systems, and organizes the data in a central database. The central database is the basis for reporting and query functions. Authorized MCAC personnel will have the ability to:
    1. Query license plate or partial license plate information in the system and view the image and location of matches;
    2. View maps with the location of plate reads and alarms;
    3. View statistical reports on reads and alarms;
    4. View reads and alarms for a specific geographic area and time frame; and
    5. Produce a geographic map of the plates that were searched.

D. Manual Inputs

  1. License plate information connected to crimes reported after the LPR automatic "Hot List" twice-daily upload (e.g., lookouts for stolen vehicles, AMBER alerts, or other wanted vehicles, not yet in NCIC) shall be accomplished through a manual input of the information in the LPR Operations Center system.
  2. Prior to authorizing the manual input of license plate information, the Watch Supervisor, LPR Program Administrator, or their respective designees, shall ensure the information is related to a specific criminal investigation or to an officer safety concern.
  3. The manual entry shall be documented on the "Hot List" log, located in the "LPR" folder on the MCAC IT Network "Common Drive".
  4. In order to ensure the accuracy of the "Hot List" for manually inserted license plates, each shift Supervisor or designee shall verify the logs accuracy. Manual entries are required to be removed following the automatic upload of NCIC and MVA wanted plates (if applicable) or if the wanted status of the plate has changed before the automatic upload.
    1. The LPR Operations Center System Hotlist Management tool does not automatically remove the inserted plates and therefore a separate query of the manually inserted hot list will be necessary.
  5. For manual entries that pertain to ongoing investigations (which are not automatically uploaded through NCIC or MVA), the manually inserted license plate shall remain on the LPR Operations Center server until advised by the requesting investigator to remove it. Periodic audits of the "Hot List" log shall be conducted by the LPR Program Administrator or designee.

E. Audit Logs

  1. All transactions and queries of the system are logged in MEMEX and are subject to review at any time. Anyone found to misuse the system is subject to disciplinary action.
  2. The primary goal of maintaining audit logs is to deter and discover any abuse or misuse of a LPR system or the Operations Center.
  3. Operation Center files shall be audited and evaluated at least yearly through an independent auditor to be determined by the Director.
  4. When a file has no further informational value and meets no other legal requirement for retention, it shall be destroyed.
  5. In order to facilitate the periodic and random audits necessary to monitor user compliance with laws and policies, audit logs should include certain information. Specifically, queries to the Operations Center should be logged and include:
    1. The identity of the user initiating the query;
    2. The license plate number or other data elements use to query the LPR system
    3. Date and time of the inquiry; and
    4. The response to the user's query.


  1. LPR Program Administrator
    1. The LPR Program Administrator, as appointed by the Director, MCAC, will be responsible for the following:
      1. Oversee and administer the LPR program, including storage and management of all LPR data systems;
      2. Ensure stored data is purged from the LPR System Operations Center one year after it has been entered, unless determined to be of evidentiary value. (Refer to Paragraph VII.B.2 and B.2.a above);
      3. Confirm LPR data is purged in accordance with this policy through random audits;
      4. Act as the authorizing official for individual access to the data collected on the Operations Center server and to conduct LPR stored data queries;
      5. Ensure appropriate training in accordance with this policy of all personnel authorized access to LPR Operations Center prior to using the system;
      6. Ensure all training is documented;
  2. Watch Section Personnel
    1. The MCAC Watch Section will be responsible for the following:
      1. At the beginning of each shift, ensure all "Hot Lists" have been updated in the Operations Center. This function is currently programmed to perform automatically (see "Hot List" definition for details);
      2. Check the Operations Center "Car download status" at least once per shift for excessively large numbers of files aborted or waiting to be transferred;
      3. Notify the LPR Program Administrator or MCAC Information Technology Specialists of any problems encountered;
      4. The Watch Section Supervisor or Designee shall ensure accurate records of all LPR RFS requests entered by Watch Section personnel are documented and retained in accordance with established Center policy.
  3. MCAC Information Technology Section
    1. The MCAC Information Technology Specialists will be responsible for system security and the maintenance of the LPR Operations Center server. In addition, the Section will:
      1. Ensure that LPR data is backed up daily and monitored for abnormal operations.
      2. Act as the MCAC representative with the contracted vendor for system related issues.



Case Management Systems: Case management databases, tips and leads files, records management systems, criminal history records, and other non-intelligence databases used and maintained by the MCAC are not Criminal Intelligence Files and are not required to comply with 28 CFR Part 23 ( Much of the information stored in these databases tends to fall into one of two categories: uncorroborated information (such as tips) or fact-based information (such as arrest or criminal history information).

Criminal Activity: A behavior, action, or omission that is punishable by criminal law. A crime is a public, as opposed to a moral, wrong; it is an offense committed against (and thus punishable by) the state or the community at large.

Criminal Case Support: Those administrative or analytic activities that provide relevant data to law enforcement personnel regarding the investigation of specific criminal activities or trends, or specific subject(s) of criminal investigations.

ELSAG: ELSAG North America Law Enforcement Systems, the contracted provider of the LPR Operations Center System.

Hot List: The hot list is a file which contains the license plate numbers of stolen vehicles, stolen tags, AMBER, SILVER or BLUE alerts, lists of license plate numbers known to be associated with specific individuals such as wanted persons or missing persons (i.e. wanted for homicide, rape, robbery, child abduction, etc.), terrorist watch lists. The Motor Vehicle Administration also provides Suspended or Revoked Registrations. This hot list is scheduled to be updated twice daily and does not rely on real-time communications with State or Federal data sources. LPR hot lists are compiled to serve agency-specified needs. Manual Entry is always available, allowing additions for specific license plates. The hot list is essential to LPR systems as it is required in order to notify law enforcement that a vehicle on the list is near an LPR camera.

Legitimate Law Enforcement Purpose: Means the investigation, detection, or analysis of a crime or a violation of the Maryland Motor Vehicle (MVA) laws or the operation of Terrorist or Missing or Endangered person searches or alerts.

License Plate Reader (LPR): The License Plate Reader Technology consists of an infrared strobe and high speed cameras combined with computer algorithms capable of converting the images of license plates into computer readable data. LPR systems use cameras to capture images of vehicles and their license plates, from both mobile patrol vehicles or from fixed positions, converts them to text and compares them quickly to a large list of plates of interest. This system also records the location, date and time of each license plate read. The resource is available as a tool, allowing the law enforcement officer to identify the last known contact with a vehicle and also to report the list of vehicles located in a specific area at a given time. When a target plate is located, the user may be notified with a message alert tone.

License Plate Reader (LPR) Program Manager/Administrator: The employee designated by the Executive Director of the Maryland Coordination and Analysis Center (MCAC), who is responsible for the oversight of the LPR Program.

License Plate Reader (LPR) Operations Center System: The system that manages the data collected from LPR systems (fixed and mobile), downloads hotlists and automatically secures the license plate data in a central server. This management is automatically run without user intervention. The Operations Center database provides an inquiry tool, tracks history, analyzes and manages license plate data. The MCAC will manage the LPR System Operations Center and assume the role as a central clearinghouse for all license plates scanned by various law enforcement agencies. The Operations Center will also manage the distribution and update of hotlist data, in addition to providing a storage and query tool for the plate information being collected in the field.

MEMEX: The Maryland Coordination and Analysis Center's internal information management system, a software tool capable of consolidating data and information, managing cases and providing an audit trail.

Need-to-Know: Requested information which is pertinent and necessary to the requestor agency in initiating, furthering, or completing an investigation.

Non-Criminal Intelligence Files: Data, frequently raw and unanalyzed, compiled by law enforcement agencies in the conduct of normal business, such as suspicious activity tips, numbers and types of calls received from the public in agency call centers, situational awareness/officer safety information, etc. These files may also include open source (i.e. news media and publically accessible internet) information. Such files do not include personally identifying information (PII) such as name, Social Security Number, birth date and address, etc. with regard to any particular individual.

Right-to-Know: Requestor has official capacity and statutory authority for the information being sought.

Requests for Information/Service (RFI/S): Defined as a request for any information or service, routinely provided by the MCAC, which is made by a law enforcement or homeland security or public safety agency such as: general, unclassified or classified information, suspect targeting information, basic or advanced research (database and information system checks), analysis of a terrorism or violent crime issue, and notification of officials of general and/or specific intelligence information or threats.