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Back to Archives | Back to November 2011 Contents 

Technology Talk

Verifying and Establishing Identity: A Priority in Public Safety Operations

By David J. Roberts, Senior Program Manager, IACP Technology Center

very day, in jurisdictions throughout the United States and around the world, law enforcement officers are confronted with a common and compelling question: “Who is the person with whom I am dealing?” When a law enforcement officer initiates a routine traffic stop or answers a call for service—things that occur thousands of times each and every day—one of the officer’s first objectives is to establish the identity of the person or persons with whom they are dealing.

Establishing identity is important because it enables the officer to determine whether the person, if operating a motor vehicle, has a valid and appropriate driver’s license; whether the person poses an immediate threat to the officer or to others; and whether the person is wanted in this or another jurisdiction. Additionally, it enables the officer to determine whether there are any restrictions on the driver’s license of that person and whether the subject has a criminal record that may have relevance to the current situation (for example, whether the person is on probation with a curfew or geographic restrictions or other conditions).1

If the person has a driver’s license or another photo-based state identification card, the officer can compare the photo and demographic factors with the appearance of the person and normally make a reasonably accurate determination of the likelihood that the person is in fact who he or she claims to be. If the person does not have a valid driver’s license or another photo-based state identification card, however, the officer may not be able to immediately and accurately determine an identity. A wanted person may elude apprehension if the officer is unable to complete identification in the field.

Technological advances in science have greatly enhanced the ability of law enforcement officers and agencies to establish and verify the identity of persons with biometric precision. The emergence of automated fingerprint identification systems (AFIS) and live-scan fingerprint capture devices revolutionized latent fingerprint processing and enabled law enforcement to positively identify suspects and close cases that previously would have remained open and unsolved. Moreover, this technology is becoming more mobile, enabling officers to remotely capture digital fingerprint impressions in the field to establish or verify the identity of the person with whom they are dealing.2 Breakthroughs in DNA typing have similarly enabled police to identify and eliminate suspects and solve open cases from the past.3 Facial recognition, voice recognition, iris scanning, hand geometry, palm prints, gait analysis, and a host of other biometric measures have also proven effective in establishing and verifying the identity of record subjects.4

Identification versus Identity Verification

Establishing positive identification is essential in order to facilitate accurate and appropriate decision making at virtually every stage of the justice enterprise—from arrest and correctional intake to the setting of bail, adjudication, sentencing, confinement, correctional admission, discharge, and community supervision. In establishing the positive identity of a person, a distinction must be made between identification and identity verification.

Identification essentially addresses the question, “Who is this person?” The challenge facing the official is to determine the identity of a person based on such criteria as a name; demographic factors such as age, sex, race, date of birth, ethnicity, height, weight, and distinguishing marks; and biometric measures such as fingerprints, palm prints, facial recognition, voice recognition, iris scans, and DNA profiles. Identification involves making one-to-many comparisons in which the official captures information regarding the subject and compares it with a database of similar information obtained from other persons with the goal of finding a match.

Identity verification, in contrast, asks the question, “Is this the person he or she claims to be?” Identity verification involves making one-to-one comparisons of demographic factors and biometric measures on the subject at hand with an existing record to determine whether there is a match that confirms that the person is who he or she claims to be.

Identity is usually established with biometric precision. When people are arrested, their fingerprints are taken and compared with other fingerprints on file. An arrested person’s fingerprints are compared to all fingerprints stored in the local jurisdiction’s or the state’s fingerprint file. If identical fingerprints are discovered in an existing record, fingerprint examiners will verify the match, confirm the identity of the person, and the existing criminal history and other records will be updated with the new arrest information, including any different names or variations of the subject’s name and other information that was reported. If there is no record of prior arrest, a new state identification number typically will be assigned, a new criminal history record will be created, and the fingerprints captured will be added to the jurisdiction’s fingerprint database. Much of this process is now greatly expedited through the use of AFIS and live-scan fingerprint capture workstations.

Technological Advances

All states, and many local jurisdictions, either have their own AFIS systems or are part of a regional AFIS system. The Western Identification Network, for example, is a multistate AFIS system providing regional AFIS capabilities in Alaska, Idaho, Montana, Nevada, Oregon, Utah, Washington, Wyoming, California, and various federal agencies.5 The Federal Bureau of Investigation operates the Integrated Automated Fingerprint Identification System (IAFIS), which serves as a national fingerprint and criminal history system that provides round-the-clock service to local, state, and federal partners.6 With a database including fingerprints and criminal histories on more than 70 million people in the criminal file and more than 31 million civil fingerprints, the IAFIS is the largest biometric database in the world.

Fingerprints, of course, are only one biometric factor that can be used to verify or establish positive identity. Collecting baseline biometric measures of a person (e.g., capturing a digital image of a person’s fingerprints by use of a live-scan fingerprint scanner), registering that information into an accessible computer with appropriate analytic and comparison software, and deploying subsequent capture technologies enable agencies to verify the identity of the person by comparing the baseline, enrolled fingerprint image or other biometric measure to one that is captured from the person at a new event. Similar enrollment and comparisons can be made using any number of unique biometric measures including facial recognition, iris scans, hand geometry, speech verification, and even vascular recognition.

The FBI’s Next Generation Identification (NGI) program is building state-of-the-art biometric identification services that will include multimodal functionality.7 Rather than rely on a single biometric measure such as a fingerprint, the NGI program will include additional forms of “biometric identification, such as palm prints, iris scans, facial imaging, scars, marks, and tattoos—in one searchable system.”8 Expanding the collection and integration of multiple forms of biometric identification expedites the searching process, improves the quality of identifications, and helps ensure officer and public safety by quickly and reliably verifying or establishing identity.

Another tool that has proven beneficial in assisting law enforcement officers in verifying the identity of persons with whom they are dealing is the International Justice and Public Safety Information Network (Nlets) Interstate Sharing of Photos program.9 Nlets, a nonprofit organization owned by the states, provides the tools and the services necessary to share driver’s license photos and correctional images and information with law enforcement agencies throughout the nation.10 Pushing driver’s license images and correctionalphotos to officers working remotely in the field provides crucial information in real time.

It should be noted that fingerprints and other biometric measures are not always captured in every criminal case. In some situations—for example traffic offenses—a law enforcement officer may issue a summons or a citation rather than take the person into physical custody. In such circumstances, the defendant’s fingerprints or other biometric measures are not captured or linked to the charging document at initial contact and, therefore, will not be available in the future for identity verification. Typically, the officer will issue a summons or a citation relying on a state-issued identification instrument, such as a driver’s license or a state identification card, which usually includes a photograph of the person and physical descriptors (for example, age, sex, race, height, and weight). From a practical standpoint, however, the person who appears in court may or may not be the same person to whom the officer issued the summons or citation. The officer may be present in court and able to remember details regarding the person who was issued the summons or citation, and certainly the summons or citation will include details regarding the person’s name, driver license number, and other physical descriptors. In other cases, a suspect wanted in connection with a crime may be missing or may have eluded capture, or a prosecutor may file a complaint against a person with no prior arrest. If no official records containing biometric measures related to the suspect presently exist, identification may be difficult to establish.

Name Search Efficacy

In situations where no previously recorded biometric measures exist to establish or confirm a person’s identity, a careful examination of other factors may prove reasonably effective in establishing or verifying identity. Such factors as name, sex, race, age, date of birth, height, weight, hair color, eye color, and distinguishing marks and tattoos often serve as reasonable surrogates for scientifically validated biometric measures. Studies of the efficacy of name searches—which actually include not only name but also sex, race, date of birth, and social security number, where available—for criminal history records of various civil applicants indicate that name searches are reasonably effective, though not nearly as effective as biometric-based searches.

In one national study of 93,274 civil applicants in Florida, where both name search and fingerprint searches were completed, name search alone would have produced 1,252 (11.7 percent) false negatives—that is, where applicants had criminal records but name searches alone indicated that they did not; and 4,562 (5.5 percent) false positives—that is, where applicants did not have criminal records but name searches alone would incorrectly indicate that they did.11 While these figures do not compare with the exceptional accuracy rates achieved by fingerprint searches (99 percent to 99.5 percent), the figures do indicate that searching by name alone is nevertheless reasonably accurate (88.3 percent to 94.5 percent) when no biometric alternative exists.


Establishing identification also is essential in discovering and retrieving information regarding persons from multiple data sources. One of the core functions of justice information sharing programs generally is the ability to initiate a universal or federated query of multiple information systems. Users should be able to initiate a single query regarding a person—based on name, demographic information, and hopefully multiple biometric measures—that is capable of accessing multiple information systems and returning consolidated results. Users should have the ability to query all systems to which they have authorized access, as well as the ability to select specific systems that will be interrogated for the query.

Establishing and verifying identity with biometric precision is an enduring and crucial operational function for effective law enforcement and public safety. Officers must know the identity of the person with whom they are dealing for their own safety and for that of the general public, as well as to ensure accurate and effective decision making. Fortunately, the technological tools have emerged, the core information systems have or are being built, and the information sharing infrastructure has evolved vto enable real-time identification. ■


1It should be noted that “confirming and fixing an individual’s identity under all circumstances in a timely manner” was identified as one of the high-priority criminal justice technology needs in a 2010 report of the National Institute of Justice (High-Priority Criminal Justice Technology Needs, 2010, NCJ 230391, Washington, DC: U.S. Department of Justice, Office of Justice Programs, National Institute of Justice (July 2010), 21, (accessed October 12, 2011).)
2Patricia Wolfhope, “Mobile Biometric Devices: What the Future Holds,” The Police Chief 78 (September 2011): 38-40, (accessed October 12, 2011). Also see MIDAS and Lantern Mobile Fingerprinting Projects: Equality Impact Assessment Consultation Paper (London, UK: National Policing Improvement Agency, June 2009).
3John Butler, Fundamentals of Forensic DNA Typing (London, England: Elsevier, 2010). For a costeffectiveness analysis of expanding the use of DNA collection and typing to other high-volume crimes such as burglary, see John K Roman et. al., The DNA Field Experiment: Cost-Effectiveness Analysis of the Use of DNA in the Investigation of High-Volume Crimes, NCJ 222318, Urban Institute Justice Policy Center, U.S. Department of Justice (April 2008), (accessed October 12, 2011). The Combined DNA System (CODIS) and theNational DNA Index System (NDIS), operated by theFederal Bureau of Investigation (FBI), provide DNAprofiles contributed by local, state, and federal forensiclaboratories. In recent years, states have created repositoriesof DNA profiles obtained from convicted offendersand arrestees. These repositories can be searched(1) when forensic DNA is collected at a crime sceneon an unknown perpetrator in an effort to identify asuspect and (2) against a jurisdiction’s forensic indexto determine if two or more incidents are linked by acommon offender. The FBI’s NDIS and CODIS programsenable jurisdictions to search a national databaseof DNA profiles contributed by local, state, and federalforensic laboratories. For more information, see (accessed October 12, 2011).
4Thomas J. Baker, “Biometrics for Intelligence-Led Policing: The Coming Trends,” The Police Chief 28 (April 2011): 38–45, (accessed October 12, 2011).
5Detailed information regarding the Western Identification Network can be found at (accessed October 14, 2011).
6More information regarding the Federal Bureau of Investigation’s IAFIS system can be found at (accessed October 14, 2011).
7For detailed information regarding the Next Generation Identification program, see (accessed October 12, 2011).
8Federal Bureau of Investigation, “Beyond Fingerprints: Our New Identification System,” January 26, 2009, (accessed October 12, 2011).
9Chelsea S. Keefer, “Nlets Interstate Sharing of Photos,” The Police Chief 76 (July 2009), (accessed October 12, 2011).
10More information regarding Nlets can be found at (accessed October 12, 2011).
11Interstate Identification Index Name Check Efficacy: Report of the National Task Force to the U.S. Attorney General (Sacramento, Calif.: SEARCH, The National Consortium for Justice Information and Statistics, July 1999), NCJ 179358, (accessed October 12, 2011).

Please cite as:

David J. Roberts, "Verifying and Establishing Identity: A Priority in Public Safety Operations," Technology Talk, The Police Chief 78 (November 2011): 76–77.

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From The Police Chief, vol. LXXVIII, no. 11, November 2011. Copyright held by the International Association of Chiefs of Police, 515 North Washington Street, Alexandria, VA 22314 USA.

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