Law Officer Volume 5 Issue 4 License plate recognition (LPR) technology has established itself as a valuable tool to assist law enforcement in combating crime. LPR systems give law enforcement the ability to search for stolen cars, stolen license plates or vehicles that may be driven by wanted felons in a fraction of the time it would take using traditional means. LPR is opening a new chapter in law enforcement, turning street poles and standard patrol vehicles into advanced surveillance platforms.
Traditionally, when an officer needs to validate a license plate, they either call in the plate number to dispatch or enter the number into a patrol vehicle computer. The officer must then wait for the dispatcher or computer system to return pertinent results. In this system, the officer can run a check of only one vehicle at a time. As a result, license plate checks tend to be a slow, cumbersome process. A dedicated, full-time officer using this method to check plates may run only a couple hundred plates in a single shift.
LPR systems, however, are capable of scanning thousands of license plates during a single shift and are limited only by the number of plates that come in view of the system's cameras. In large urban areas, for example, several LPR systems working together can read a nearly unlimited number of license plates every day.
LPR systems use cameras and a computer to automatically capture passing vehicle license plates and check the plates against a preloaded database of plates linked with some type of criminal activity, such as the National Crime Information Center (NCIC) or other database. For example, the database can contain plates from stolen vehicles, cars driven by wanted subjects or vehicles associated with an AMBER alert; the system can also match for license plates reported stolen.
When a plate match occurs, the system sends an alert to the operator, indicating a "hit." The system operator checks to see if the LPR system accurately read the state and number on the plate. In mobile LPR systems, a patrol officer visually confirms the LPR system's hit; in fixed systems, the dispatcher confirms the hit through a captured picture of the vehicle.
Testing & Evaluation
To validate the potential capabilities and effectiveness of LPR technology, the City of Georgetown Police Department (GPD) in Georgetown, S.C., worked with the Department of Homeland Security's Federal Emergency Management Agency (FEMA) Operational Validation (OpVal) Program to evaluate LPR systems in an operational environment.
Situated on the coast of South Carolina, Georgetown is home to approximately 9,000 people. With Myrtle Beach to the north and Charleston to the south, Georgetown sits on the main thoroughfare, U.S. Highway 17. To the outsider, Georgetown appears to typify "Main Street America." Tourism and hospitality, as well as steel and paper manufacturing, are mainstays of income for the community. Using Georgetown as an operational testbed for LPR equipment provided the opportunity to show how this technology can impact smaller communities.
Getting Started with LPR Technology
There are three types of LPR systems to choose from: fixed, mobile or portable. The GPD and the OpVal Program worked together to determine which type of LPR systems would be procured, and what types of criminal activities the LPR system would identify.
GPD selected two fixed systems and two mobile systems. One fixed system was placed in the north end of town, reading plates entering the city from Myrtle Beach, while the other fixed system was placed at the south end of town, reading plates entering from Charleston. This allowed the GPD to gather plate information for each vehicle that entered the city on its busiest thoroughfare. A terminal for each fixed LPR system was installed in the county and city dispatch center, where the systems could be monitored 24 hours per day, seven days a week.
The two mobile LPR systems were permanently installed in two patrol vehicles. Multiple officers were trained on how to use the systems as part of their daily operations. The mobile LPR systems gave the GPD LPR capability anywhere it was needed.
The next step: Determine what databases would be uploaded into the LPR systems. After evaluating the available databases, the GPD decided to focus its attention on stolen vehicles, stolen plates, AMBER alerts and criminal wants/warrants using the NCIC database.
Overcoming the 'Big Brother' Mentality
Any time a municipal, county, state or federal government considers installing camera systems, the first reaction from many circles is often that the government is "spying" on its citizens. LPR systems have faced close scrutiny concerning violations of privacy. However, LPR systems acquire and process information from vehicle license plates in essentially the same manner as a police officer, visually acquiring the license plate number and then checking it against a database.
At first, the Georgetown City Council was apprehensive about installing the LPR systems, fearing a negative public reaction. To alleviate these fears, the GPD briefed the City Council members on the way in which the LPR systems functioned and the applications for which they would be used.
When the first arrest attributed to the LPR systems occurred, attitudes began to change. The Council began to see the LPR systems as a tool that had the potential to make the city safer.
On the Move
In Georgetown, officers transfer the NCIC database from a computer at the police station and load it into the mobile LPR system in a patrol vehicle via a USB memory stick. The systems were set up to provide both visual and audio alarms when the system hits on a plate. When the LPR system signals a suspect plate, the officer verifies the plate image to ensure the system read the plate correctly. The officer also contacts dispatch and verifies that the captured plate still has an active warrant. Once the hit is confirmed, the offi cer initiates a traffic stop on the suspect vehicle.
Fixed LPR Systems
The fixed systems provide the city with constant surveillance of inbound traffic using cameras mounted on a telephone pole at one end of the city and on a traffic light pole at the other end of the city. The specially configured cameras can monitor entire traffic lanes. A wireless network was configured to seamlessly transfer information from the cameras to the dispatch center. The hits are displayed on a special terminal at the central dispatch center. The LPR terminal is located alongside the police dispatcher's computer-aided dispatch (CAD) system so as not to distract dispatchers from their normal duties.
Having access to the LPR systems in the dispatch center enables dispatchers to receive alerts on vehicles, verify hits and send out officers to respond to the suspect vehicle's last known location.
LPR in Action
The LPR systems have become an indispensable tool for the GPD. The original skepticism about how the systems would work and how effective they would be were quickly erased. The systems work so well that a hit for a stolen plate from one of the fixed systems registered while the technicians were still configuring the system. The vehicle was spotted, and the stolen plate verified with the dispatch office. Within a few hours after installation, the first LPR-associated arrest was made.
In another incident, the system alerted on a license plate belonging to a reported stolen vehicle. After verifying the hit, officers were dispatched to the suspect vehicle's last known location. Within minutes, officers were able to locate the stolen vehicle and conduct a traffic stop. The individuals in the suspect car stated that the vehicle was not theirs and that it was loaned to them by a friend. The vehicle, however, was reported as stolen, so the subjects in the car were placed under arrest and charged with possession of a stolen motor vehicle. A subsequent search of the vehicle uncovered a set of burglary tools. As a result, each of the vehicle's occupants received an additional charge of possession of burglary tools.
In yet another incident, one of the fixed systems alerted on an Iowa license plate from a vehicle whose owner, a registered sex offender, had an outstanding warrant in Iowa. After locating the vehicle and conducting a traffic stop, the responding officer found the male subject in the front passenger seat and an unknown female driving the vehicle. After running the female's information, police discovered that she too had an active warrant out of Iowa. Both suspects were placed under arrest and subsequently extradited to Iowa.
The GPD's LPR systems work around the clock, and one alert for a stolen vehicle came through the dispatch center at 0425 HRS. All available units were notified of the stolen vehicle's location and direction of travel. When the officers intercepted the vehicle and attempted to conduct a traffic stop, the driver fled. A high-speed pursuit ensued across two counties. After joining the pursuit, the Myrtle Beach police were eventually able to force the vehicle off the road and take the suspects into custody.
Pros & Cons
The GPD couldn't have predicted just how successful the LPR systems were going to be. Over the course of a few months, arrests associated with the LPR systems dramatically increased. In addition, many of the vehicles recovered as a result of the LPR systems were in much better condition than those located through traditional means. Previously, recovered stolen vehicles were commonly found destroyed or burned on the side of the road. Now, officers are able to recover the stolen vehicles in decent condition. This usually comes as a surprise to the insurance companies, the owners of the stolen vehicles and to the police agencies who initially reported the vehicles as being stolen.
From the operations perspective of the GPD, the one drawback of the technology is that the LPR systems require more resources than anticipated. According to GPD personnel, the LPR systems generate so many valid alerts that they consider it a necessity to have a dedicated LPR team to ensure a rapid and proper response.
GPD's LPR system is also garnering interest in neighboring cities and counties; several have called the GPD for assistance in attempting to find vehicles that may have been used in the commission of a crime. In one instance, a murder occurred in Myrtle Beach and the suspect was reportedly heading toward Georgetown. Myrtle Beach police had a partial tag number and provided it to the GPD, which entered the number into the LPR system. The GPD was able to rapidly determine that the vehicle had not entered Georgetown through the areas covered by the LPR systems, helping the neighboring agency narrow its search area.
In other instances, the mobile units have been used in mutual aid exercises, including supplemental support for the Myrtle Beach bike weekend. After seeing the systems in action, the surrounding jurisdictions have all expressed interest in purchasing LPR technology for their respective departments.
Lessons Learned
Based on the GPD's experience, the return on investment for an LPR system depends on the amount of resources an agency has available to support it. The GPD initially decided to limit checks to the NCIC records, but additional databases will likely be added in the near future. It's expected this will significantly increase the workload on dispatchers and officers alike because of the identification of wanted vehicles that would otherwise have gone unnoticed. According to GPD staff, agencies may want to consider an incremental approach to adding databases to determine the impact on overall workload.
Another lesson from the GPD experience: The implementation and operation of LPR systems require a degree of technical knowledge and support. GPD found the mobile systems and the in-car equipment easy to use. However, the fixed LPR systems and the associated LPR servers require advanced networking, database and computer systems knowledge to install and maintain. Although the technical support from the LPR vendors was excellent, GPD recommends that agencies ensure their departmental information technology staff has the necessary resources to properly support the systems before procuring LPR technology.
In only a few months of operation, the GPD's LPR systems have read more than a million license plates, leading to 20 arrests. With the added database records, the GPD expects those numbers to dramatically increase. LPR technology has made Georgetown a safer place for its residents and has increased the department's investigative and policing capabilities.
FYI: FEMA & OpVal
Visit the SAVER Program Web site at https://saver.fema.gov for more information on FEMA OpVal or to view additional reports on LPR systems or other technologies.