Reference Work Entry

Encyclopedia of Biometrics

pp 49-55

Background Checks

  • Peter T. HigginsAffiliated withHiggins, Hermansen, Banikas, LLC


Vetting; Credit check; Personal information search; Preemployment screening; Disclosure check; Criminal record search; Criminal history check


There are multiple types of Background checks that all involve reviewing past, recorded behavior:
  1. 1.
    Job Applicants: When people apply for a position of trust (e.g., a school teacher, a lawyer, or bank teller) a background check is part of the way of determining if the applicant is suitable – a positive result. These are known as Applicant or Civil Background Checks. In the US:
    1. (a)

      If there is a state or federal law requiring a national check then applicant fingerprints (with minimal supporting biographic information) can be submitted to the Federal Bureau of Investigation (FBI) for a search.

    2. (b)

      If the applicants are seeking federal employment then their biographic data and fingerprints can be submitted to the FBI for a search.

    3. (c)

      If the applicants are applying for a job not covered by a state or federal law they are restricted to commercial background checking services – companies that have aggregated financial, court, motor vehicle and other records.

  2. 2.

    Applicants for Credit: When people apply for credit cards or a large financial commitment (e.g., a mortgage) a background check is part of the way of determining if the applicant is suitable – a positive result. These are known as Credit Checks and are performed by commercial background checking services.

  3. 3.

    Applicants for Government Benefits: When people apply for a visa, passport, drivers license, social security and other benefits governments use varying levels of background checks to weed out fraud (e.g., multiple applications with different identities but for the same subject), previously denied persons, etc. Other than possibly checks for visas, most of these checks say nothing about the suitability of a person for trustworthiness.

  4. 4.

    Criminals: In the criminal justice community Background Checks are used when a person is arrested to determine if an arrestee already has a criminal record that they are hiding – a negative result that will be used in setting bail, sentencing, etc. In the US:

  5. 5.

    Arrestee fingerprints (with minimal supporting biographic information) can be submitted to the FBI for a search.

Background Checks are primarily based on textual information (e.g., name and date of birth) searches of bank, court, credit card issuer, and other files or textual searches and in some cases are combined with biometric based (e.g., fingerprint) searches of criminal or undesirable persons (e.g., persons previously deported) records.

The ANSI/IAI 2-1988 American National Standard for Forensic Identification Glossary of Terms and Acronyms defines “criminal history check” as “A search of name indices and/or fingerprint files to determine whether or not a subject has a prior criminal record.

The same American National Standard glossary defines “criminal history” as “A chronological summary of an individual’s criminal activity which may include the dates of the activity, the individual’s name, aliases and other personal descriptors, the identities of the reporting agencies, the arrest charges, dispositions, etc.

The UK Criminal Records Bureau performs an Enhanced Disclosure Check (the same check as the Standard Disclosure but with a local police record check) to establish criminal backgrounds.

A Credit Check is an automated credit record search conducted through various major credit bureaus.


Background checks became important to law enforcement about the time that large numbers of people started moving to cities as a by-product of the Industrial Revolution. Prior to that few people ever ventured far form their birthplace – a place where they were known and their history was known. The need to link people to their criminal histories drove police forces in London, Paris, and Buenos Aires to examine identification methodologies such as fingerprint recognition and anthropometry in the late 1800s – the surviving approaches are now classified as members of the science called biometrics. Simon Cole’s 2001 book provides a good history of criminal identification [1].

In the post World War II era international travel became far more common than before the war. A parallel can be drawn with the movement during the Industrial Age within countries – now criminals and terrorists were freely crossing borders – hoping to leave their criminal/terrorist records behind. Even if the world’s police records were all suddenly accessible over the Internet – they would not all be in the same character set. While many are in the Roman alphabet, others are in Cyrillic, Chinese characters, etc., this poses a problem for text search engines and investigators. Fortunately biometrics samples are insensitive to the nationality or country of origin of a person. Thus a search can be theoretically performed across the world using fingerprints or other enrolled biometric modalities. Unfortunately the connectivity of systems does not support such searches other than on a limited basis – through Interpol. If the capability to search globally were there the responses would still be textual and not necessarily directly useful to the requestor. One response to the challenge of international travel has been that nations collect biometric samples, such as the United Arab Emirates does with Iris Recognition, Overview, at their points of entry to determine if a person previously deported or turned down for a visa is attempting to reenter the country illegally.

A wide variety of positions of trust in both the public and private sectors require verification of suitability either as a matter of law or corporate policy. A person is considered suitable if the search for background impediments is negative. A position of trust can range from a police officer or teacher; to a new corporate employee who will have access to proprietary information and possibly a business’s monetary assets; or to an applicant for a large loan or mortgage. Certain classes of jobs are covered by federal and state/provincial laws such as members of the military and school teachers/staff.

A background check is the process of finding information about someone which may not be readily available. The most common way of conducting a background check is to look up official and commercial records about a person. The need for a background check commonly arose when someone had to be hired for high-trust jobs such as security or in banking. Background checks while providing informed and less-subjective evaluations, however, also brought along their own risks and uncertainties.

Background checks require the “checking” party to collect as much information about the subject of the background check as is reasonably possible at the beginning of the process. Usually the subject completes a personal history form and some official document (e.g., a driver’s license) is presented and photocopied. The information is used to increase the likelihood of narrowing the search to include the subject, but not too many others, with the same name or other attributes such as the same date and place of birth.

These searches are typically based on not only an individual’s name, but also on other personal identifiers such as nationality, gender, place and date of birth, race, street address, driver’s license number, telephone number, and Social Security Number. Without knowing where a subject really has lived it is very hard for an investigation to be successful without broad access to nationally aggregated records. There are companies that collect and aggregate these records as a commercial venture.

It is important to understand that short of some biometric sample (e.g., fingerprints) the collected information is not necessarily unique to a particular individual. It is well known that name checks, even with additional facts such as height, weight, and DOB can have varying degrees of accuracy because of identical or similar names and other identifiers. Reduced accuracy also results from clerical errors such as misspellings, or deliberately inaccurate information provided by search subjects trying to avoid being linked to any prior criminal record or poor financial history.

In the US much of the required background information to be searched is publicly available but not necessarily available in a centralized location. Privacy laws limit access in some jurisdictions. Typically all arrest records, other than for juveniles, are public records at the police and courthouse level. When aggregated at the state level some states protect them while others sell access to these records. Other relevant records such as sex offender registries are posted on the Internet.

For more secure positions in the US, background checks include a “National Agency Check.” These checks were first established in the 1950s and include a name-based search of FBI criminal, investigative, administrative, personnel, and general files. The FBI has a National Name Check Program that supports these checks. The FBI web site [2] provides a good synopsis of the Program:
  • Mission: The National Name Check Program’s (NNCP’s) mission is to disseminate information from FBI files in response to name check requests received from federal agencies including internal offices within the FBI; components within the legislative, judicial, and executive branches of the federal government; foreign police and intelligence agencies; and state and local law enforcement agencies within the criminal justice system.

  • Purpose: The NNCP has its genesis in Executive Order 10450, issued during the Eisenhower Administration. This executive order addresses personnel security issues, and mandated National Agency Checks (NACs) as part of the preemployment vetting and background investigation process. The FBI is a primary NAC conducted on all U.S. government employees. Since 11 September, name check requests have grown, with more and more customers seeking background information from FBI files on individuals before bestowing a privilege – whether that privilege is government employment or an appointment, a security clearance, attendance at a White House function, a Green card or naturalization, admission to the bar, or a visa for the privilege of visiting our homeland.…

  • Function: The employees of the NNCP review and analyze potential identifiable documents to determine whether a specific individual has been the subject of or has been mentioned in any FBI investigation(s), and if so, what (if any) relevant information may be disseminated to the requesting agency. It is important to note that the FBI does not adjudicate the final outcome; it just reports the results to the requesting agency.

  • Major Contributing Agencies: The FBI’s NNCP Section provides services to more than 70 federal, state, and local governments and entities.… The following are the major contributing agencies to the NNCP:
    • U.S. Citizenship and Immigration Services – Submits name check requests on individuals applying for the following benefits: asylum, adjustment of status to legal permanent resident, naturalization, and waivers.

    • Office of Personnel Management – Submits name check requests in order to determine an individual’s suitability and eligibility in seeking employment with the federal government.

    • Department of State – Submits FBI name check requests on individuals applying for visas.… [2]

In the US government background checking process, a credit checkis included in most background investigations except the basic NACI investigation required of employees entering Non-Sensitive (Level 1) positions [3].”

Background checks were once the province of governments. Now commercial companies provide these services to the public, industry, and even to governments. These commercial checks rely on purchased, copied, and voluntarily submitted data from second and third parties. There are many commercial companies that accumulate files of financial, criminal, real estate, motor vehicle, travel, and other transactions. The larger companies spend substantial amounts of money collecting, collating, analyzing, and selling this information.

At the entry level, customers of these aggregators include persons “checking out” their potential roommates, baby sitters, etc. At the mid-level employers use these services to prescreen employees. At the high end the data is mined to target individuals for commercial and security purposes based on their background (e.g., financial and travel records.) The profiling of persons based on background information is disturbing in that the files are not necessarily accurate and rarely have biometric identifiers to identify people positively. For an example of the problem, there is no need to look further than the news stories about post 9–11 name-based screening that kept Senator Kennedy on the no-fly list because he shared a name with a suspected person – and that was a government maintained file.

Historically the challenge in background checking has been (1) when people usurp another person’s identity that “checks out” as excellent, (2) when people make up an identity and it is only checked for negative records not for its basic veracity, and (3) when persons try to hide their past or create a new past using multiple identities to gain benefits or privileges they might otherwise not be entitled to receive. A second identity could be created by simply changing their date and place of birth, of course it would not have much “depth” in that a simple check would reveal no credit history, no driver’s license, etc. yet for some applicants checking is only to determine if the claimed identity has a negative history or not – not to see if the person really exists. All of these challenges render many name or number-based (e.g., social security number) background checks ineffective.

Several countries, states, and provinces are undertaking one relatively simple solution to stolen identities. As more and more records become digital, governments can link birth and death records – so a person cannot claim to be a person who died at a very early age and thus having no chance of a negative record. People were able to use these stolen identities as seeds for a full set of identification documents. Governments and financial institutions are also requiring simple proof of documented residence such as mail delivered to an applicant from a commercial establishment to the claimed address and a pay slip from an employer. Denying people easy ways to shift identities is a critical step in making background checks more reliable.

The most successful way to deal with these challenges has been to link persons with their positive (e.g., driver’s license with a clean record) and negative history (e.g., arrest cycles) biometrically. The primary systems where this linkage is being done are in the provision of government services (motor vehicle administration and benefits management) and the criminal justice information arena (arrest records and court dispositions). Currently, few if any financial records are linked to biometric identifiers and the major information aggregators do not yet have biometric engines searching through the millions of records they aggregate weekly. The real reason they have not yet invested in this technology stems primarily from the almost total lack of access to biometric records other than facial images. This provides some degree of privacy for individuals while forcing credit bureaus to rely on linked textual data such as a name and phone number, billed to the same address as on file with records from a telephone company, with an employment record.

The inadequacy of name-based checks was redocumented in FBI testimony in 2003, regarding checking names of persons applying for Visas to visit the US. Approximately 85% of name checks are electronically returned as having “No Record” within 72 hours. A “No Record” indicates that the FBI's Central Records System contains no identifiable information regarding this individual…” This response does not ensure that the applicants are using their true identity but only that the claimed identity was searched against text-based FBI records – without any negative results.

The FBI also maintains a centralized index of criminal arrests, convictions, and other dispositions. The data is primarily submitted voluntarily by the states and owned by the states – thus limiting its use and dissemination. The majority of the 100 million plus indexed files are linked to specific individuals through fingerprints. The following information about the system is from a Department of Justice document available on the Internet [4].

This system is an automated index maintained by the FBI which includes names and personal identification information relating to individuals who have been arrested or indicted for a serious or significant criminal offense anywhere in the country. The index is available to law enforcement and criminal justice agencies throughout the country and enables them to determine very quickly whether particular persons may have prior criminal records and, if so, to obtain the records from the state or federal databases where they are maintained. Three name checks may be made for criminal justice purposes, such as police investigations, prosecutor decisions and judicial sentencing. In addition, three requests may be made for authorized noncriminal justice purposes, such as public employment, occupational licensing and the issuance of security clearances, where positive fingerprint identification of subjects has been made.

Name check errors are of two general types: (1) inaccurate or wrong identifications, often called “false positives,” which occur when all three name checks of an applicant does not clear (i.e., it produces one or more possible candidates) and the applicant’s fingerprint search does clear (i.e., applicant has no FBI criminal record); and (2) missed identifications, often called “false negatives,” which occur when the three name checks of an applicant’s III clears (i.e., produces no possible candidates) and the applicant’s fingerprint search does not clear (i.e., applicant has an FBI criminal record). Although errors of both types are thought to occur with significant frequency – based on the experience of state record repository and FBI personnel – at the time when this study was begun, there were no known studies or analyses documenting the frequency of such errors.

In contrast, fingerprint searches are based on a biometric method of identification. The fingerprint patterns of individuals are unique characteristics that are not subject to alteration. Identifications based on fingerprints are highly accurate, particularly those produced by automated fingerprint identification system (AFIS) equipment, which is in widespread and increasing use throughout the country. Analyses have shown that AFIS search results are 94–98% accurate when searching good quality fingerprints.

Because of the inaccuracies of name checks as compared to fingerprint searches, the FBI and some of the state criminal record repositories do not permit name-check access to their criminal history record databases for noncriminal justice purposes.

Where Do Biometrics Fit In?

When executing a background check there are several possible ways that biometric data can be employed. As seen governments can collect large samples (e.g., all ten fingers) to search large criminal history repositories. The large sample is required to ensure the search is cost effective and accurate. The time to collect all these fingerprints and extract the features can be measured in minutes, possibly more than ten, while the search time must be measured in seconds to deal with the national workloads at the central site.

Other programs such as driver’s license applicant background checks are sometimes run using a single facial image. These are smaller files than fingerprints, collected faster using less costly technology, but have somewhat lower accuracy levels thus requiring more adjudication by the motor vehicle administrators.

As companies (e.g., credit card issuers) start to employ biometrics for convenience or brand loyalty – they are very likely to use the biometrics not just for identity verification at the point of sale but to weed out applicants already “blacklisted” by the issuer. These biometric samples will need to be of sufficient density to permit identification searches and yet have a subset that is “light weight” enough to be used for verification in less than a second at a point of sale.

Temporal Value of Background Checks

In the US under the best conditions a vetted person will have “passed a background check” to include an FBI fingerprint search, a NAC, a financial audit, personal interviews, and door-to-door field investigation to verify claimed personal history and to uncover any concerns local police and neighbors might have had. This is how the FBI and other special US agencies and departments check their applicants. Unfortunately, this is not sufficient. Robert Hanssen, Special Agent of the FBI was arrested and charged with treason in 2001 after 15 years of undetected treason and over 20 years of vetted employment.

Even more disturbing is a 2007 case where Nada Nadim Prouty pleaded guilty to numerous federal charges including unlawfully searching the FBI’s Automated Case Support computer system. Ms. Prouty was hired by the FBI in 1999 and underwent a full background check that included fingerprints. In 2003 she changed employers, joining the CIA where she underwent some level of background check. Neither of these checks nor earlier checks by the then INS disclosed her having paid an unemployed American to marry her to gain citizenship.

Without being caught, criminals have the same clean record as everyone else, with or without biometrics being used in a background check. While FBI agent’s fingerprints are kept in the FBI’s AFIS system, those of school teachers and street cops are not. This means if any of them were arrested only the FBI’s employees’ fingerprints would lead to notification of the subject’s employer. Rap (allegedly short for Record of Arrests and Prosecutions) sheets are normally provided in response to fingerprint searches. A relatively new process called Rap-Back permits agencies requesting a background check to enroll the fingerprints such that if there is a subsequent arrest the employer will be notified. Rap-Back and routine reinvestigations addresses part of the temporal problem but in the end there is no guarantee that a clean record is not a misleading sign – just an indicator of no arrests, which is not always a sign of trustworthiness.

Privacy Aspects

Performing a complete and accurate background check can cause a conflict with widely supported privacy laws and practices. The conflicts come from most “privacy rights” laws being written to inhibit certain government actions not to uniformly limit commercial aggregation and sharing of even questionable data on a background-data-for-fee basis.

Robert O’Harrow’s book [5], points out two serious flaws on the privacy side of the commercial background check process.
  • “Most employees who steal do not end up in public criminal records. Dishonest employees have learned to experience little or no consequences for their actions, especially in light of the current tight labor market,” ChoicePoint tells interested retailers. “A low-cost program is needed so companies can afford to screen all new employees against a national theft database.” The database works as a sort of blacklist of people who have been accused or convicted of shoplifting [6].

  • Among other things the law restricted the government from building databases of dossiers unless the information about individuals was directly relevant to an agency’s mission. Of course, that’s precisely what ChoicePoint, LexisNexis, and other services do for the government. By outsourcing the collection of record, the government doesn’t have to ensure the data is accurate, or have any provisions to correct it in the same way it would under the Privacy Act [7].

These companies have substantially more information on Americans than the government. O’Harrow reports that Choice Point has data holdings of an unthinkable size:
  • Almost a billion records added from Trans Union twice a year

  • Updated phone records (numbers and payment histories) from phone companies – for over 130 million persons

  • A Comprehensive Loss Underwriting Exchange with over 200 million claims recorded

  • About 100 million criminal records

  • Copies of 17 billion public records (such as home sales and bankruptcy records)

The United Nations International Labor Organization (ILO) in 1988 described “indirect discrimination” as occurring when an apparently neutral condition, required of everyone, has a disproportionately harsh impact on a person with an attribute such as a criminal record.” [8] Thus pointing out the danger of cases where criminal records “include charges which were not proven, investigations, findings of guilt with non-conviction and convictions which were later quashed or pardoned. It also includes imputed criminal record. For example, if a person is denied a job because the employer thinks that they have a criminal record, even if this is not the case [9].”

This problem is recognized by the Australian government, which quotes the above ILO words in its handbook for employees. The handbook goes on to say, “The CRB recognises that the Standard and Enhanced Disclosure information can be extremely sensitive and personal, therefore it has published a Code of Practice and employers’ guidance for recipients of Disclosures to ensure they are handled fairly and used properly” [10].


Background checks are used for preemployment screening, establishment of credit, for issuance of Visas, as part of arrest processes, in sentencing decisions, and in granting clearances. When a biometric check is included, such as a fingerprint-based criminal-records search, there can be a higher degree of confidence in the completeness and accuracy of that portion of the search.

Seemingly secure identification documents such as biometric passports do not imply a background check of the suitability of the bearer – but only that the person it was issued to is a citizen of the issuing country. These documents permit positive matching of the bearer to the person the document was issued to – identity establishment and subsequent verification of the bearer.

It is unfortunately easy to confuse the two concepts: a clean background and an established identity. The US Government’s new Personal Identity Verification (PIV) card, on the other hand, implies both a positive background check and identity establishment. The positive background check is performed through a fingerprint-based records search. The identity is established when a facial image, name, and other identity attributes are locked to a set of fingerprints. The fingerprints are then digitally encoded and loaded on the PIV smart card; permitting verification of the bearer’s enrolled identity at a later date, time, and place.


Background checks are a necessary but flawed part of the modern world. Their importance has increased substantially since the terrorist attacks on 9/11 in the US, 11-M in Spain, and 7/7 in London. Governments use them within privacy bounds set by legislatures but seem to cross into a less constrained world when they use commercial aggregators. Industry uses them in innumerable process – often with little recourse by impacted customers, employees, and applicants. Legislators are addressing this issue but technology is making the challenge more ubiquitous and at an accelerating rate.

Biometric attributes linked to records reduce the likelihood of them being incorrectly linked to a wrong subject. This is a promise that biometrics offers us – yet the possible dangers in compromised biometric records or systems containing biometric identifiers must be kept in mind.

Related Entries

Fingerprint Matching, Automatic

Fingerprint Recognition, Overview

Fraud Reduction, Application

Fraud Reduction, Overview


Identity Theft Reduction

Iris Recognition at Airports and Border-Crossings

Law Enforcement


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© Springer Science+Business Media, LLC 2009
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