License Plate Readers for Law Enforcement

Opportunities and Obstacles

Keith Gierlack, Shara Williams, Tom LaTourrette, James M. Anderson, Lauren A. Mayer, Johanna Zmud

ResearchPublished Jul 2, 2014

Law enforcement agencies across the country have quickly been adopting a new technology to combat auto theft and other crimes: automated license plate reader (LPR) systems. These systems can capture the image of the license plate of a passing vehicle and compare the plate number against official "hotlists" that show an array of infractions or reasons why it may be of interest to authorities. But because LPR technology is relatively new in the United States, opportunities and obstacles in its use in law enforcement are still under exploration. To examine issues about this technology, RAND conducted interviews with law enforcement officers and others responsible for procuring, maintaining, and operating the systems. Champions of LPR technology exist at many levels, from tech-savvy officers who use it every day, to chiefs who promote it, to other officials and policymakers who believe LPR technology is a significant force multiplier for police departments. Challenges exist, however, to realizing more widespread acceptance and use of the technology. Chief among these are privacy concerns related to the retention and potential misuse of LPR data, technical and bureaucratic impediments to sharing data among law enforcement agencies, and constraints on the availability of staffing and training needed to support LPR systems.

Key Findings

License plate reader (LPR) systems, while initially used to detect stolen vehicles and plates, are increasingly being tapped for a variety of investigations.

  • Authorities can retrieve LPR data to determine vehicles in the vicinity of a crime scene.
  • The system can provide photos of those vehicles to confirm suspect alibis.
  • LPR data can be used to analyze crime patterns.

Many privacy advocates have challenged the practice of storing LPR data not associated with a specific crime.

  • Some police departments lack clear guidance on storing plate data, leaving privacy advocates to fear it can be kept and retrieved indefinitely.
  • Some privacy advocates, departments, and lawmakers have moved to codify police procedures on recording these data; some have banned the technology's use outright.

LPR systems can be beneficial in providing assistance in any type of investigation, provided the necessary data are available to support the systems.

  • Systems with the most database access and longest retention policies are the most beneficial because they can provide the greatest number of alerts and the ability to retrieve LPR data over time across law enforcement activities.
  • System maintenance and data storage can increase cost. If an agency's database can be made part of existing information technology infrastructure, its maintenance costs can be lessened.


  • Estimate and secure necessary funding for the entire lifecycle of LPR technology.
  • Ensure that sufficient infrastructure is in place to handle different types of data promptly and frequently.
  • Develop policies for system data use, access, and storage.
  • Integrate LPR systems into daily agency operations and learn from other agencies how to expand their use to more analytical operations.
  • Develop model memoranda of understanding for agencies to share LPR data.
  • Identify tradeoffs between privacy rights and law-enforcement uses.

Order a Print Copy

Page count
120 pages
List Price
Buy link
Add to Cart


Document Details

  • Availability: Available
  • Year: 2014
  • Print Format: Paperback
  • Paperback Pages: 120
  • Paperback Price: $24.95
  • Paperback ISBN/EAN: 978-0-8330-8710-2
  • Document Number: RR-467-NIJ


Chicago Manual of Style
Gierlack, Keith, Shara Williams, Tom LaTourrette, James M. Anderson, Lauren A. Mayer, and Johanna Zmud, License Plate Readers for Law Enforcement: Opportunities and Obstacles. Santa Monica, CA: RAND Corporation, 2014. Also available in print form.

The research described in this report was sponsored by the National Institute of Justice and was conducted in the Safety and Justice Program within RAND Justice, Infrastructure, and Environment.

This publication is part of the RAND research report series. Research reports present research findings and objective analysis that address the challenges facing the public and private sectors. All RAND research reports undergo rigorous peer review to ensure high standards for research quality and objectivity.

This document and trademark(s) contained herein are protected by law. This representation of RAND intellectual property is provided for noncommercial use only. Unauthorized posting of this publication online is prohibited; linking directly to this product page is encouraged. Permission is required from RAND to reproduce, or reuse in another form, any of its research documents for commercial purposes. For information on reprint and reuse permissions, please visit

RAND is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.