License plate recognition (LPR) systems are increasingly commonplace in the U.S., but the Cincinnati Police Department (CPD) has long been on the cutting edge of this technology. Purchasing eight mobile LPR units from Federal Signal's PIPS Technology in 2007, the CPD has since built a database of more than 3 million license plates. The department has taken the technology to the next level, providing an example of how to expand and maximize the license plate data collected.
The Back End
What makes CPD's use of this technology stand out from others?
The feedback I've gotten from other agencies is that it s our back end the database, says Heather Whitton, senior computer programmer analyst for CPD and LPR project manager. I got the impression that other agencies that had LPR back in 07 were using it only for stolen cars and parking citations. They hadn't dipped into the power of the back end. Whitton recalls that her agency thought about how it could harness that power from the very beginning.
Now, CPD is moving ahead to make its database even more powerful. CPD utilizes its LPR database in conjunction with other databases, such as a database of information collected at each traffic stop. All these databases helped with the success of the LPR system, Whitton points out. The hot lists that CPD uses are all pulled into databases: The central server manages all hot lists. Some are pulled once a day; others are updated three to five times a day, she says. All of this is done automatically.
Ultimately the data collected through the LPR units may be used for crime analysis.
Whitton explains that the vehicles with LPR units are used for two functions: street strength, in which the officer with the LPR can use immediate alerts to make stops, and information gathering. Regarding both street strength and data gathering, Whitton says, If you're going to invest in the technology, use it and use it effectively.
For example, she says, The [squad cars with mobile LPR units] aren't just used for driving around looking for stolen vehicles and parking violations. But if you have the officer drive the same beat every day, you don't get the value of the system. Change it up, and allow the officers to drive throughout the district. This way, each LPR vehicle will capture more plates and information, all of which are incorporated into the database.
We make a point to drive around bars and clubs. We even drove around a motorcycle gang when it was in town, Whitton says. The LPR units capture license plates that the CPD can check should an incident occur. Most of that data, no one even looks at, Whitton points out. We only access it when something happens.
She recalls a gang funeral in which the CPD knew that members of two gangs would be attending or nearby. We drove this vehicle around the streets, capturing license plates near the church and the cemetery. The data helped us identify the vehicles of gang members involved in shooting an FBI agent s car.
The technology is also used routinely at CPD s impaired-driving checkpoints. This allows almost every plate to be run and vehicles photographed, Whitton says. In this case, it's a really great officer safety tool. The officer running the checkpoint doesn t have time to check every plate, but the LPR does it in seconds.
Officers in LPR-equipped vehicles will get a near-instant audible and visual alert if a scanned plate shows up on a hot list.
The software is continually running, explains Whitton. The camera captures the plate; the software converts that to text. The computer system checks the license plate number against all CPD databases. If it finds a match, it sends an alert back to the unit in seconds.
However, a plate that generates an LPR alert doesn t mean the officer can stop the vehicle.
All officers have to sign a pledge that they will not stop based solely on LPR, says Whitton. It's not considered probable cause. You must do further verification.
The issue is partly lag-time in the LPR check of databases, which are not live. Because LPR is scanning so many plates so quickly, [the mobile units] don t go straight into the database, Whitton says. Rather, officers driving LPR vehicles must upload the latest data from the central server onto their vehicle s unit at the beginning of their shift. At the end of their shift, they download the data they ve captured that day. Because the database isn t updated in real time throughout the day, officers with LPR units may be alerted to a vehicle reported stolen yesterday but would not know that that vehicle had been recovered earlier today.
Another issue: LPR doesn t differentiate between various states license plates, so officers especially in a region like Cincinnati, which borders two other states must double-check that the plate alert is for the right state.
Anyone who runs an effective LPR system has to understand that it s a tool. It s not the end-all, be-all, Whitton says. You ve got so many variables. The system is used just to tell the officer to check something out.
Plans to Expand
CPD has big plans in the works to keep its technology working efficiently. We re in the process of creating a regional database that will be significantly larger, Whitton says. The new database will be shared by agencies in 12 counties in the tristate SOSINK region (southwest Ohio, southeast Indiana and northern Kentucky).
Thirty-seven agencies in the SOSINK region have received grant money from their state s Homeland Security office to purchase LPR equipment. Another 14 or 15 plan to purchase equipment with their own funds. We ll have over 50 agencies in a short time, says Whitton. And some agencies that can t afford a system have asked if they can search the database. They ll have a regionwide database that they can query.
All the LPR data from these agencies will pour into in a single regional database, providing a central source for all hot lists. That benefits everybody, Whitton points out. Also, all the data will be downloaded to the same database. That will be a very valuable tool for our investigators.
Coordinating with dozens of agencies is difficult work, but Whitton reports, The cooperation I ve been getting from all the agencies has been amazing. Everyone is very excited about this. She also points out, We ve already laid the groundwork at CPD for officer training and policies, so expanding [throughout the region] will be a lot easier.
The initial phase of the expansion getting all agencies online with the regional database is set to be completed by March 2010. Whitton points out that agencies with grant money have a deadline for spending their money and using the new equipment.
After the agencies are working with their single data system, Whitton says, We ll start looking at fixed cameras. The plan calls for placing 80 fixed LPR cameras pointed at interstate highways throughout the SOSINK region. Placing these units entails meeting many requirements from various governmental agencies, as well as environmental protection studies, and site visits to evaluate infrastructure.
In addition to plans for additional mobile units and fixed cameras, Whitton is looking into supplemental portable LPR units. This is a brand new system from Federal Signal, she explains. They can be mounted on a vehicle, then moved to another. One could be shared among a group of smaller agencies.
Although the CPD never relies solely on LPR to stop a vehicle or build a case, the license plate data collected has helped in many arrests. Here are two examples:
While conducting LPR training with Officer Cotterman, Heather Whitton pulled up the image of a recent alert: a CPD detective was searching for a plate number provided by a witness in a gang homicide. The plate had been read the day before by the District 4 LPR system. Officer Cotterman immediately identified the exact apartment building where the vehicle was parked, and quickly located the suspected vehicle. He waited for the occupants of the vehicle, and once they began to drive away he made a traffic stop for a traffic violation. Through this stop and subsequent arrest, investigators were able to question the suspect and hold him until he was positively identified as the murder suspect and charged.
After a woman was robbed at an ATM and threatened with a gun, she provided the plate number of the getaway vehicle to police. Officers searched the LPR database and found 11 hits in the system, with the vehicle frequenting the McMillan area. Officers immediately began to patrol the area and spotted one of the suspects, the driver of the getaway vehicle. The getaway driver confessed and identified the other suspect. The other suspect is still at large and the getaway vehicle hasn t been located. The plate of the vehicle has since been put in the LPR database to alert CPD should the vehicle be spotted.
Although the CPD has already made excellent use of its LPR technology, plans to expand access to a regional database should prove groundbreaking. Keep an eye on this type of pooling of plate data, because it will likely prove to be the key to effective use of LPR.
Jane Jerrard is a Chicago-based writer.