License plate recognition (LPR) systems aren't new the technology was invented in 1976 at the United Kingdom's Police Scientific Development Branch but recent advancements have vastly improved their accuracy. In addition, a more compact, mobile unit has made LPR practical for wider application in law enforcement. In fact, the systems have become so effective in assisting officers in locating stolen vehicles that some insurance companies are helping to fund their installation or expansion.
The ability to capture photos, however, isn't of much use until that information is compared to a database. Jefferson Parish Sheriff s Office (JPSO), protecting just fewer than a half-million citizens in a suburban area outside of New Orleans, found a distinctive approach to the data-transfer issue.
The sheriff's agency could have used air cards or microwave a typical data transfer method used by other agencies but wanted something more reliable and with better coverage. So JPSO turned to its local cable provider. Capitalizing on the broadband voice, data and video transfer capabilities already in place throughout the Parish, JPSO partnered with Cox Business to use its network.
How It Works
LPR systems are offered by several vendors for a range of applications beyond law enforcement, including transportation agencies that use it to access travel time and traffic patterns. Parking lots also use LPR to track vehicle inventories and provide security.
For law enforcement, an LPR system replaces the tedious task of manually entering a license plate number to check against a database of stolen vehicles, BOLOs and AMBER Alerts. The technology can also be used to provide DUI surveillance, drug enforcement or even augment homeland security efforts.
The system uses specialized software to help the camera locate the license plate in its field of view. Infrared and color cameras, from either fixed or mobile locations, capture an image of the license plate. Many current systems can capture an image of a license plate from a vehicle traveling up to 160 mpg.
By employing a complex algorithm to isolate the license number from the plate background, an optical character recognition (OCR) program can convert the digital image of the license plate into text. System accuracy varies from state to state, but most rates for the current systems run in the 90% range once it has been customized for that state's plates. The final step is to check the text against one or more databases for a hit. The captured images are stored in a database that can include a date and time stamp and global positioning coordinates.
Still, the technology isn t error free. The image can be affected by such factors as damaged or dented license plates. The time of day and weather can lead to blurred images and snow or dirt can obscure the license plate numbers and letters. Further, some vanity plates and those issued to antique cars can be difficult for the system to interpret.
In Jefferson Parish, stationary cameras mounted to telephone poles, street light poles and traffic bars photograph and record every vehicle that passes their fields of view. Each unit houses two specially designed cameras: a color camera to photograph the rear portion of the vehicle and an infrared camera that s used by the OCR to capture and decode the license plate number.
A similar system is used on patrol cars. A series of four smaller versions of the cameras are affixed to the light bar, providing mobile surveillance. The cameras are adjusted to cover vehicles from multiple directions and angles, including in the lane to the right or left of the patrol car, either moving away from or toward the officer. Another angle photographs parked vehicles.
As the officer drives around, the LPR system is tagging every plate in its field of view, says Capt. Emile Larson. According to Larson, a single patrol car can tag an estimated 4,000 vehicles per shift. The force multiplier is unbelievable, he says.
The software for the mobile cameras includes a global positioning device that records the location of each photo, along with the date and time stamp.
Information gathered by the cameras is wirelessly transmitted over a virtual private network (VPN) to a main server located at JPSO headquarters, which also houses the Agency of Motor Vehicles central database. The information is run against several databases, including stolen vehicles, missing persons, probation and parole wanted lists, felony wanted lists and any other hot crimes. Using the photo archives, officers can also dial up a specific camera to review vehicles passing a location just before and just after a known crime.
In addition to the license plate, Larson says the quality of the photos and the multiple camera angles on the mobile units pick up unique identifiers on the vehicle, making it easier to spot. Depending on the angle of the camera, you can see broken tail lights, rear end damage or bumper stickers, he says.
Data Transfer
After deciding to purchase an LPR system from PIPS Technology, Larson says JPSO began to investigate options for getting the data from the field to the server. Digital cable was the fastest of the available options and local provider Cox Business already had the network in place.
Since our network is already built out in the neighborhoods they wanted to target, JPSO has the flexibility to go wherever they need to, says Vincente Boreros, a member of the Cox Business Account Team who works with the agency.
The fixed cameras used by JPSO are configured to the Cox Cable lines. The mobile cameras use a modem with a specific IP address that transmits the data to JPSO's server.
Larson says JPSO is pleased with the service. Reliability is excellent, he says.
There have been a few weather-related failures for cameras located inside the metal utility boxes, due in large part to the extreme Louisiana heat. However, Larson has been happy with the round-the-clock technical support from Cox.
JPSO pays a monthly fee to Cox of $50 per modem for use of the network. Other ongoing costs include a monthly fee to the power provider of $5 per unit.
Specific to the Industry
Although the LPR program is a distinctive application of its current network, Boreros says it fits the company s mission to provide service to all possible users. It s an innovative solution using our existing technology, he says. We have the staff to work directly with government agencies and interface with their technology, he adds.
Since October 2008 when the LPR system was installed, JPSO reports it has recovered 121 vehicles, apprehended 89 criminals and seen the number of stolen vehicles drop by 46%. The system has also provided deputies with leads for burglaries, homicides and fugitive investigations.
According to Larson, the LPR program has been so successful that the agency has already expanded from 32 cameras to a total of 57 fixed location and 11 mobile cameras, and it has plans to purchase 16 more units by the end of the year.
By applying an innovative solution to a current tech nology, the Jefferson Parish Sheriff s Office is able to streamline the data transfer process of its LPR program. The net result is a fast, reliable system with proven benefits. Technology has become our newest feet on the street. With real-time links from the crime database to cameras throughout the parish, we are more likely to apprehend suspects during the critical hours immediately following an incident, Larson says.
A Thoughtful Approach
By Dale Stockton
I recently had the opportunity to visit Jefferson Parish Sheriff s Office (JPSO) and view firsthand the good work it's doing with LPR. This agency is truly making great use of this amazing technology to solve crimes and put a dent in the bad-guy business. I spent an entire day at the agency and visited with Chief Deputy John Thevenot and Capt. Emile Larson. Their enthusiasm was contagious as they explained how the system had made such a difference in the effectiveness of policing some of their most challenging areas.
We had identified 17 violent neighborhoods in the parish, Thevenot said. These areas had limited access. Although these 17 areas are only 8% of our reporting grid, they re responsible for 34% of the violent crime shootings, aggravated burglaries, aggravated assaults, etc. We realized these areas had limited access, and if we could encapsulate these areas on the ingress, we could be more effective.
This is where the idea of LPR came in. Thevenot had heard about the technology and had seen equipment at conferences. He and Larson put forward a plan to use a combination of fixed and mobile LPRs, but it stalled due to funding challenges. Their homework paid off, however, when the agency received federal grant money, and Sheriff Newell Norman gave them the go-ahead to buy 25 cameras. Larson carefully analyzed the target areas and identified key ingress points. When he was finished, he had 30 locations that would require 32 cameras. The sheriff had confidence in the program and gave the approval to buy all 32 cameras along with the OK to buy 11 mobile LPR units, each equipped with four cameras.
The initial challenges came with dealing with the various agencies to get approval to mount the cameras. Using existing utility poles, agency employees were able to mount the cameras along with the power supplies and cable modem in an adjacent weatherproof box. Not surprisingly, the sideways rain and extreme heat and humidity of the area made for some initial problems that had to be worked through. Nonetheless, the system quickly proved its worth.
One of the features JPSO decided to add to its system was an instant notification to agency PDAs (Blackberries) whenever there was an alert on a vehicle. Sure enough, while we were visiting, the alerts went off. Larson showed me the message indicating the location, the plate read and even the picture of the vehicle picked up by the LPR. In this particular case, the suspect vehicle triggered two other fixed camera alerts before it was spotted by a patrol unit. After a short chase and the involvement of an air unit, two suspects were in custody along with a stolen van full of property taken earlier in a residential burglary. Impressive.
More cameras are being added to the system, and the parish will soon have well more than 50 fixed cameras operating. The large number of cameras and the massive amount of data collected has created a need for a robust data storage system, and the agency is in the process of building a server based on SAN storage and running Microsoft 2008 Sequel Server Enterprise edition. We brought in an expert to design this, and we see a lot of potential in doing it this way, Thevenot said.
Support for the technology has spread as officers and investigators have learned just how valuable the data can be. The agency has plans to help some of the police agencys within the parish acquire mobile LPR units to further the effectiveness. There have even been inquiries from some specific citizen groups wanting to support the acquisition and installation of an LPR system in their neighborhood.
The bottom line: The Jefferson Parish installation provides a model for other jurisdictions. If you d like to see a video giving an overview of their program, a copy of a newscast is available at www.youtube.com/watch?v=wLMB9hsIKEQ.
Teresa McCallionEMT-B, is a freelance public safety writer in Bonney Lake, Wash.