By Anthony Abdalla
Introduction
As the prevalence of Automated License Plate
Recognition (ALPR) systems continue to increase
among law enforcement agencies within the
United States and around the world, so do
policy issues regarding data collection, use,
and retention. Complicated by the fact that the
United States lacks a national policy regarding
these issues, individual law enforcement
agencies are left to examine and implement ALPR
policies individually. This issue paper will
examine ALPR technology and related policy
concerns in the hope of increasing dialog and
debate for issues surrounding this important
technology.
Technology
Overview
Automated License Plate Recognition (ALPR)
technology (also known as Automated Number
Plate Recognition (ANPR) technology in the
United Kingdom) was developed in 1992 at
Cambridge University in the United Kingdom in
response to terrorism (Gaumont & Babineau,
2008). The technology automates a core law
enforcement process that traditionally has been
left between police officers in the field and
police dispatchers in a communications center.
Officers no longer need to communicate a
license plate via police radios to dispatchers,
or typed into their mobile data terminals, in
order for the plate to be checked against
various criminal databases. The proven license
plate recognition technology exists to automate
the license plate checking process and thereby
increase the efficiency and accuracy of law
enforcement agencies worldwide.
ALPR technology can be thought of as a system of
hardware and software components that when used
collectively, read images from license plates
utilizing optical character recognition (OCR).
Hi-speed, infrared enabled cameras capture
license plate images and sophisticated OCR
software extracts the license plate characters
from the images. These scanned images are then
typically used to search a license plate
against various law enforcement databases for
possible involvement in criminal activity and
then stored in an ALPR database for data mining
purposes at a later time.
Policy Issues
As the ALPR technology matures, especially in the
United States, privacy concerns have arisen
regarding the collection, use, and retention of
the data. Privacy rights advocates have
increasingly questioned the method in which the
data is collected, how and what it is used for,
along with the length of time the data is
retained. It has now become a necessity among
law enforcement agencies that employ ALPR to
have polices that specifically address these
concerns.
Civil liberties questions surround the issue of the
collection of data in the United States. In
Portland, Oregon, where ALPR technology is
being used, the associate director of the
Oregon chapter of the American Civil Liberties
Union, Jan Carson, has concerns over its use.
“If the collection of data was specifically
tailored to the investigation of a crime, I
don’t think we would have any problem with
that,” Carson said. “But simply collecting
information on where and when people are
located, I think is a real invasion of
privacy.” (Redden, 2008, 11).
The question really becomes whether or not the
collection of the data violates the United
States Constitution’s 4th Amendment which
guarantees individuals the right to be free
from unreasonable searches and seizures. On its
face, it appears to be no constitutional
violation of the fourth amendment as there is
no reasonable expectation of privacy in a
publicly visible license plate. The United
States Tenth Circuit Court of Appeals has twice
ruled that, “because they are in plain view, no
privacy interest exists in license plates.”
(Hubbard, in press). The Sixth Circuit also
recently reached a similar conclusion
(Hubbard). Based upon the aforementioned
decisions, it would appear that policy
directing officers to only capture publicly
visible license plates would be appropriate.
Another aspect of data collection that requires policy
intervention is in regards to hit verification.
As OCR interpretation of the license plate
captures is not yet one-hundred percent
accurate, policy safeguards should be
implemented in order to minimize risks
associated with misreads. The State of
Wisconsin requires potential users of their
ALPR abstracts to sign an ALPR agreement that
mandates verification of an ALPR hit by making
a live TIME system inquiry and follow normal
hit confirmation rules (Coleman, 2008). This
process of checks and balances effectively
reduces the chances of adverse action being
taken against somebody as a result of an ALPR
misread.
A lack of standardization in the retention of the data,
especially among United States law enforcement
agencies, greatly contributes to the privacy
rights debate. For example, the National ANPR
Data Centre in the United Kingdom stores
national ANPR related data for a period of 5
years (Lewis, 2008). The Royal Canadian Mounted
Police (RCMP) stores hit data for two years and
non-hits for 90 days in accordance with
Canada’s Privacy Act (Gaumont & Babineau,
2008). In the United States, there is no
national standard for ALPR data retention and
is therefore left up to each individual law
enforcement agency to determine their
respective policies. Regardless of the chosen
length of time the data is retained, a
comprehensive ALPR policy should address data
retention timeframes for hit and non-hit data.
Lastly, some concerns have been raised over the use of
the ALPR data that has been obtained. Each ALPR
“read” is date and time stamped along with
capturing the GPS coordinates of the vehicle at
the time of the read. Either in real time or at
the end of the shift, the read data is uploaded
to a central server where the information can
be queried at a later time. Privacy rights
advocates are concerned that there is potential
for innocent citizens to be spied upon at will
by law enforcement personnel. Policy specifying
that the captured data will only be used for
police investigations will go a long way to
alleviate the concerns mentioned above.
Conclusion
Automated license plate recognition technology is an
exciting and evolving technology that promises
to assist law enforcement agencies achieve
their mission of denying criminals use of our
roadways for years to come. As with any
technology of this nature, it is incumbent upon
law enforcement professionals to put into place
the necessary safeguards that will instill
public confidence that the data and subsequent
information developed from it will be used
appropriately.
About the Author
Tony Abdalla is a police sergeant with the
South Pasadena Police Department in Southern
California. In his twentieth year with the
department, he has researched, implemented, and
managed numerous technology projects for his
agency. He can be reached at tabdalla@ci.south-pasadena.ca.us.
He completed this paper during his Criminal
Justice Management studies at the Union
Institute and University.
References
Coleman, G. (2008, May). ALPR - In Wisconsin,
in use. TIME System Newsletter, 2008-2, 4.
Retrieved from http://www.doj.state.wi.us/dles/cib/forms/news/TIME_nlMay08.pdf
Gaumont, N., & Babineau, D. (2008). The role of
automatic license plate recognition technology
in policing: Results from the lower mainland of
British Columbia. The Police Chief, LXXV(11).
Retrieved from http://policechiefmagazine.org/magazine/index.cfm?fuseaction=display&article_id=1671&issue_id=112008
Hubbard, T. E. (in press). Automatic license
plate recognition: An exciting new law
enforcement tool with potentially scary
consequences. Syracuse Science and Technology
Law Reporter. Retrieved March 23, 2009, from
http://sstlr.syr.edu/wp-content/uploads/automatic-license-plate-recognition_an-exciting-new-law-enforcement-tool-with-potentially-scary-consequences.pdf
Lewis, P. (2008, September 15). Fears over
privacy as police expand surveillance project.
The Guardian. Retrieved from http://www.guardian.co.uk/uk/2008/sep/15/civilliberties.police
Redden, J. (2008, October 9). We could all be
tracked. Portland Tribune. Retrieved from
http://www.portlandtribune.com/news/story.php?story_id=122350294579016400