Beyond the John Q. Public info you can read by clicking here, you should know that a "positive identification" is not necessarily a "positive identification".  The science of friction ridge identification leaves very little room for error when professional guidelines are followed in its application... but, in any field of human endeavor (including simple math addition, subtraction, etc.) there will always be oversights. 

Every competent fingerprint expert will have an identification* verified.  Procedurally, at most agencies it is not an identification until it is verified by another competent expert.   Most state and federal level crime labs will not even inform you that a fingerprint match occurred until after the "identification" has been verified.  An exception to this rule is fingerprint card to fingerprint card identifications made in some Automated Fingerprint Identification System (AFIS) computers.  Latent print "matching" scores at AFIS sites are normally evaluated and "verified" by two human experts before the "identification" is reported. 

Never base an identification on just the matching fingerprint classification.  A matching fingerprint classification (Henry classification, NCIC classification, etc.) means only that the person printed belongs to the group of persons whose prints all have that same classification... just like sorting out a large number of persons based on sex, age, height, weight, eye color, etc.  The identification should be verified by a well qualified fingerprint expert based on a comparison of the individual characteristics in the fingerprints... not based on the classification.  In some agencies the inked print to inked print identifications are automatically reported after computerized matching in an AFIS (Automated Fingerprint Identification System) with a minimum matching "score" set so high that human intervention is not necessary.  Low score matches in an AFIS are checked and verified by humans. 

Do NOT have an arrest warrant issued based on a fingerprint "match" unless you are certain of the credentials of the expert.  Unless an ID tech at your agency was an expert before they attended schools such as the one-week FBI classification course and the one-week FBI latent print techniques course, they did NOT leave those schools as experts (the FBI issues certificates of attendance... not certificates of successful course completion).  Although American law accepts them as experts with such little training, they are not.  In court they only have to have more knowledge about fingerprints than the average man on the street to be legally qualified as an expert. 

Most fingerprint experts train for at least two or three years under the watchful eye of experienced Latent Print Examiners before they are allowed to work unsupervised on latent prints from crime scenes.  Self-training can equip an ID tech at a small department with the same two weeks of experience, 50 times over.  Also, a deputy who looks at latent prints a couple of hours per month for ten years does NOT have ten years experience... he has the equivalent of a few weeks of crime lab type experience... and it is poor quality experience if his work was not reviewed.  How much is he missing if he only takes his "idents" to someone else for verification.  He may only be identifying the prints a chimp could match and missing more difficult impressions. 

Although there are very competent fingerprint experts in America who hold no certification, over nine hundred have attained the title of Certified Latent Print Examiners from the International Association for Identification (IAI) after completion of stringent testing (most years less than 50% of those persons taking the six hour exam have passed).  In recent years the IAI has simplified the classification portion of the test and there is now no reason for any latent print examiner to avoid testing with excuses such as, "I only work with latent fingerprints and don't do filing so I can't be tested on classification."  Suspect their expertise if they use such excuses.  A part time expert with poor quality training will not be able to pass the examination. 

* In recent years, the terms positive identification and individualization (meaning absolute certainty) have been replaced in reports and testimony by most agencies/experts with more accurate terminology, including variations of wording such as the following:

A related 2014 paper titled "Individualization is dead, long live individualization! Reforms of reporting practices for fingerprint analysis in the United States" by Simon Cole, Professor at University of California, Irvine is linked here.

You will end up permanently in jail if you live in one of the "three strikes and you're out" states after the third time your fingerprints are found at the crime scene. 

The individuality of your fingerprints makes it easier to keep your arrest record separate from other convicts. 

Why are you reading this??? 

Wear gloves... we sometimes like to identify you from your shoe prints, that drop of blood by the broken window, or the many other traces of your presence left behind.

Elementary School Student 

John Q. Public 

Police Officer 

Criminal 

The general shape or overall pattern of finger and palm prints can be inherited. Family members will often have similar patterns or designs (whorls, loops, etc.) on the same fingers of their hands. The tiny details in the fingerprint ridges, however,  are not inherited and are different between all friction skin areas of all persons... even between twins. 

The overall general flow or pattern (Level 1 detail) of friction ridges on human hands and feet is governed primarily by the height and position of the volar pads formed before birth.  The formation of the volar pads is affected by inherited traits from the parents. High pads will form whorls, low pads arches, a medium height pad to one side a loop, etc. Thus twins or close relatives may have very similar ridge flow patterns (also called finger or palm print classification). 

A few related articles are listed as follows:

Heredity in Fingerprints ,G. Shahan, ID News, Vol XX, No. 4, pp. 1, 10-14. 

A Family Fingerprint Project, J.S. McCANN, ID News, May 1975, pp. 7-11. 

Inherited Characteristics In Fingerprints: (or Theory of Relativity), T. Jones, The Print, Vol 4, No. 5.
 
 

Fingerprint patterns are inherited and thus non-fingerprint experts looking in a police fingerprint file must be careful not to confuse fingerprint records of close relatives based on fingerprint classification (Level 1 detail). Likewise, a National Crime Information Center Fingerprint Classification Code (FPC) may be very similar for close relatives. 

The actual finger and palm print detail used to effect an identification is not inherited and experts have no problem differentiating even identical twins. 

See the John Q. Public answer for more details. 
 
 

Only the overall whorl, loop, etc., patterns are inherited. The police might confuse your fingerprints with your twin brother's... for about ten seconds. The moment they put a magnifying glass on them they will see obvious differences. 

Elementary School Student 

John Q. Public 

Police Officer 

Criminal 

Yes. 

It is scientific. 

Fingerprints have been collected, observed and tested as a means of reliably identifying persons for more than 100 years. 

Scientists have proven the validity of fingerprint identification, including tiny fragments, in courts throughout the world for many years. 

Yes. 

Some common definitions of science are:

The observation, identification, description, experimental investigation, and theoretical explanation of phenomena. 

Accumulated and established knowledge, which has been systematized and formulated with reference to the discovery of general truths or the operation of general laws; knowledge classified and made available in work, life, or the search for truth; comprehensive, profound, or philosophical knowledge.

Knowledge when it relates to the physical world and its phenomena, the nature, constitution, and forces of matter, the qualities and functions of living tissues, etc.

Any branch or department of systematized knowledge considered as a distinct field of investigation or object of study; as, the science of astronomy, of chemistry, or of mind.

Any domain of knowledge accumulated by systematic study and organized by general principles.

Court challenges to the scientific nature of friction ridge identification are not new and were attempted even before recent court decisions. 

Daubert hearings are the "flavor of the day" insofar as the format of fingerprint challenges. Instead of seeking their own independent expert to determine if the government erred in its incriminating identification work, Defense instead attacks the scientific validity of even making such identifications. 

Daubert Opinion States that: 

• the trial judge must still screen scientific evidence to ensure it is relevant and reliable; 
• “the focus, of course, must be solely on principles and methodology, not on the conclusions they generate;” 
• and, factors the court should consider include: 

– testing and validation 
– peer review 
– rate of error 
– “general acceptance” 

Of the Daubert criteria factors the court should consider, Defense typically attacks the "rate of error" most stringently. Unfortunately for them, in Daubert the rate of error has to do with the scientific procedure or methodology, and not with mistakes occasionally made by individual experts. 

Defense points to the low rate of success (about 50%) for experts during the testing process for certification as a Latent Print Examiner by the International Association for Identification. What Defense does NOT advertise, is that the low success rate is due to the difficulty in making enough identifications within the time allotted, and not due to erroneous identifications (though the stringent time constriction for the test could tempt a participant to guess when they are not certain). 

Defense also points to results of annual proficiency tests purchased by laboratories. The test results pointed out by Defense included a number of non-fingerprint expert results which did not accurately reflect the capabilities of certified experts and others who embrace and work within national standards. Some of the experts producing errors were merely forensic scientists (perhaps professors?) without expertise in friction ridge identification. 

Defense concentrates on terms like "tiny, smudged and distorted" crime scene finger and palm prints in an attempt to differentiate criminal evidence fingerprint work from arrest history fingerprint identifications. The assumption that crime scene impression identification is different from inked print to inked print comparisons is false. It is not unusual for crime scene friction ridge impressions to have better quality and quantity of ridge detail than the inked prints to which they are compared. It is also not unusual for the comparison of poor quality inked fingerprint cards to be as difficult as crime scene impression comparisons. The friction ridge detail is represented as "better or worse quality and quantity" information, regardless of whether the recording medium is ink, sweat, blood, oil, or digital capture using a live scan fingerprint "reader." 

FRICTION RIDGE IDENTIFICATIONS ARE MADE USING THE (ACE-V) PROCESS. 

Depending on the quality (clarity) and quality of friction ridge detail present, a fingerprint expert comparing two inked prints between arrest fingerprint cards may use ALL of the information in the questioned inked impression (on the new FP card) to effect an identification against a file print. Defense typically avoids the fact that an identification is often established between arrest FP cards using only a fraction of the friction ridge detail present in two inked prints... exactly the same way crime scene impressions are compared. 

As explained here, there is zero tolerance for identification errors in friction ridge identification. Friction ridge identification is reliable. 
 
 

Yes - Ask you supporting crime laboratory about their compliance with national and international forensic guidelines for training to competency, annual proficiency testing and other quality assurance measures.

Click here to see details of court challenges to the science of friction ridge identification. 

Challenges to science are valuable to protect society. Although it is often easy for forensic scientists to discount challenges as just more courtroom drama, such challenges are important to protect justice and help improve judicial, government and forensic processes. Persons claiming fingerprint identification is junk science include the following:

1 - Defense attorneys who don't claim the incriminating fingerprints were not made by their client, but instead that fingerprints cannot be scientifically linked to their client in a crime lab. Yes, they know they can click here and hire an independent expert with credentials as good as the government's expert for less than the cost of a Daubert hearing. 

2- Professor Simon Cole - who has written a book and multiple articles/papers on the topic. Many of his arguments and claims have good merit, but some have been challenged. In one court hearing, Simon Cole was offered the opportunity to explain his knowledge and expertise about the scientific value of fingerprint testimony. The judge ruled, ..."Even applying the Federal Court's Daubert Standard, what Dr. Cole has offered here is 'junk science"... 

3 - Professor (James Starrs) who in 1996 predicted the utter collapse of fingerprints as scientific evidence:

"The word is out and it is enough to startle, perplex and lay fingerprint examiners low. The short of it is that fingerprint identifications are worse than on the ropes.  They are down and verging on being counted out.  This citadel of forensic science is not only fissure-ridden.  It is veering towards collapse..." (by James Starrs, from the front page of his "Scientific Sleuthing Review," Vol. 20, No. 4, Winter 1996).

Professor Starrs' testimony has generally failed to convince courts his reasoning about latent print examiner testimony  is sound.

Unfortunately for you, YES. 

Unfortunately for the fingerprint experts who identified your prints, Daubert hearings are the current flavor of the month insofar as nuisance challenges your attorney can use to postpone your trial. 

Humor attempts aside, if your fingerprint was erroneously identified and that error is what incriminates you... there is a 100% chance the error can be brought to light and the record set straight. For the cost of an engine tune-up, your attorney or family can hire a certified independent expert to review the incriminating identification(s).  

The science of friction ridge identification is sound, and the same experts who tout its validity to identify criminals will work equally hard to rectify an identification error by one of "their own."  There exists zero tolerance for identification errors. 

In the very rare instance where a fingerprint identification mistake results in an erroneous criminal arrest, the agency involved is almost always very forthcoming in admitting the error (usually exposed by another agency or an independent expert). 

In recent decades, Scotland's national fingerprint forensic unit and the FBI Laboratory have both been involved in cases where their fingerprint experts made erroneous identifications causing false arrests. The resulting embarrassment and internal investigations revealed problems in the scientific process and resulted in important changes to help those laboratories (and the rest of the forensic community) improve latent finger and palm print (friction ridge) processes for greater accuracy. Both the Scottish Criminal Records Office's fingerprint experts and the FBI Laboratory learned important lessons and significantly improved their forensic processes.

Because the scientific discipline of friction ridge identification has no state or national boundaries, the truth WILL be known and incompetent or fraudulent identification practices will be revealed (unless you are unfortunate enough to live in a country with corrupt government officials and/or corrupt judicial officers/judges).

Fingerprint experts do not (or at least should not) care whether or not you committed the crime of which you are accused (they are witnesses to available information from collected evidence, not judge and jury), but they DO care whether or not the friction ridge identification linking you to a crime (or helping exonerate you) is accurate. 
 
 

Some crime laboratories do not have enough people or money to search all crime scene fingerprints in the FBI's computerized files. Some do not even have enough people or money to operate a computerized fingerprint file for their own city or county. 

Police administrators and laboratory managers operate within budgets. Money constraints cause tough decisions about distributing resources between patrol units, investigators and forensic scientists. 

Facts about the FBI's national fingerprint database, called Next Generation Identification (NGI) and formerly known as the Integrated Automated Fingerprint Identification System (IAFIS):

• It is the largest automated (tenprint) fingerprint database in the world and contains fingerprints of over 50 million criminals.
• It cost over a billion dollars (over multiple decades) to build and is the backbone of America's criminal history repository.
• NGI latent print software is free to all agencies and can be run from almost any existing desktop or laptop computer.
• The FBI provides free NGI (ULW) software training to fingerprint experts during IAI Annual Educational Conferences and in other venues upon request.
• Some states do NOT provide access for local agencies to submit searches through state law enforcement's connection to the FBI's Criminal Justice Information Services (CJIS) wide area network (WAN) .

Some examples of AFIS configurations and associated costs are:

Small Agency Stand-Alone Configuration - $60,000 to $160,000
AFIS capable of storing and searching over 20,000 finger and palm print records: starting at about $50,000
Annual AFIS supplies and system maintenance: $10,000
Full-time Certified Latent Print Examiner annual salary: $50,000 to $150,000

Small Agency Network Configuration - $50,000 to $160,000
Terminal networked with a regional or state AFIS: starting at $50,000
Annual AFIS supplies and system maintenance: $10,000
Full-time Certified Latent Print Examiner annual salary: $50,000 to $150,000

Large City Crime Lab Stand-Alone Configuration - $380,000 to $2,630,000
AFIS capable of storing and searching over 200,000 finger and palm print records: $150,000 to $2,000,000
Annual AFIS supplies and system maintenance: $30,000
Four full-time Certified Latent Print Examiners annual salary: $200,000 to $600,000

FREE - FBI Software for Agencies or Crime Labs with Expert Latent Print Examiner but no dollars for AFIS
The FBI's NGI system offers an alternative to agencies with fingerprint experts but no extra dollars for AFIS. They can use free FBI  ULW software and an existing desktop computer to prepare unsolved case latent fingerprints to be launched through their state law enforcement agency's FBI CJIS WAN. 
 

In the post-911 era, the entire criminal justice system should utilize existing national resources such as NGI. Standards, best practices and guidelines (from the FBI and OSAC) need to be followed insofar as possible. 
 
 

In addition to the John Q. Public answers here, you should know that there is NO GOOD REASON for the fingerprint experts supporting your agency to refrain from searching the FBI's national criminal fingerprint database. 

If they will search all unsolved serious cases through IAFIS, they can expect to identify at least ten percent (and probably more) of the latent prints searched. Do not take no for an answer in requiring that they begin using IAFIS.

Sometimes it is out of ignorance. 

Sometimes the pride of an under-funded agency means they would rather do a shabby job with fingerprint evidence and let cases go unsolved... than turn over evidence to another agency with modern methods and connectivity which could make them look bad.

If you are in one of those jurisdictions, stay put and hope the community doesn't wise-up and replace status quo police services with knowledgeable professionals. 
 
 

Biometric fingerprint systems are designed to identify persons who want to be identified. 

AFIS is designed to identify persons who are trying to hide their identity. 

Biometrics is a wide-ranging topic encompassing much more than just fingerprints (iris, face, voice, hand geometry, etc.), including some applications that are so novel they have never been tested in court for admissibility as a method for reliable identification.  This FAQ addresses biometric fingerprint applications.

Biometric fingerprint systems are designed to identify persons who want to be identified.  AFIS is nearly the opposite... it is designed to protect society by detecting criminals who do not want their fingerprints recognized.

Biometric systems are normally a business process.  Such systems save companies money because it is expensive to keep reissuing lost passwords or PIN numbers.  Also, biometrics offer improved security compared to the post-it notes bearing passwords often found in work cubicles or the ease of spotting someone's PIN number as they enter it into a keypad.  The most secure fingerprint biometric systems use more than just a fingerprint, such as also a PIN and a card or token.  Some systems use multiple biometrics such as iris and fingerprint. 

Biometric fingerprint systems compare the finger or fingers of a person against records in a computer or on a chip, to see if the person may be granted permission to do something such as access a computer or enter a room.  The process does not use all the information in a fingerprint that is used by forensic scientists identifying a fingerprint.  It is more like a possible, "close-enough correlation" of similarities. 

In biometric systems, it is not a problem when the system fails to identify a person’s fingerprint(s).  The person just does not get access until they try again (often two or three times in a normal work environment) and are able to present their finger(s) in such a manner as to provide an impression with better quantity and/or quality of information (perhaps not pressed down so hard, not twisted slightly, not tipped up on one edge, etc.) 

It is very common for persons using biometric systems to see a message that says “place your finger again” when the system fails to identify them regardless of how carefully they try to present their finger(s) for recording on the system.   

Although some biometric systems claim to have the ability to identify persons who are registered in the system and trying to evade detection, there are fundamental logic flaws to such claims.  For one thing, the distortion introduced by a person attempting to evade detection means that the computer matching score would be lower than normal.  Because biometric systems operate in a “lights-out” mode (meaning that there are no human fingerprint experts sitting in a room monitoring less than optimal matching score comparisons), there would often not be a high enough matching score to trigger a red-light or alarm for a potential match due to distortion easily introduced. 

Because they are “lights-out” processes, biometric systems, unlike law enforcement AFIS, can only deal with the “best” matching score between the finger(s) presented and the records on file regardless of how low the score.  Law enforcement AFIS never settles for just the “best” matching score.  In AFIS, lower scoring candidates in a list (not the the highest matching score) are very often the correct match for a person attempting to evade detection.  The lower matching score is the natural result of slight twisting or other pressure distortion introduced by the person during the printing process.  Such introduction of intentional distortion is the opposite of what biometrics are designed to deal with… biometrics are designed to ID persons who are trying to comply and trying to present good quality fingerprints so they can be granted a privilege.

The expertise required for identification of single-print searches is a completely different caliber from what is required for law enforcement AFIS "ten rolled fingerprint" searches.  Fingerprint Examiners (called Fingerprint Clerks before the job title changed) at the FBI's huge fingerprint processing center in Clarksburg, WV are not qualified to render opinions on latent print-like single print comparisons from biometric systems.  Those single-print exams are made by Latent Print Examiners such as those working in the FBI Laboratory at Quantico, VA. 

In addition to John Q. Public's answer here, you should be aware that biometric systems normally do not capture fingerprint information in a manner consistent with law enforcement fingerprint standards (i.e., ANSI/NIST, FBI EFTS, Interpol). 

Before 9-11, biometric systems almost universally touted that they were not law enforcement systems, that consumers need not fear that police might use the systems for “tracking” because only a small portion of fingerprint information (called a template) was maintained in the system to effect the comparison, and that template was definitely not compatible with law enforcement AFIS. 

After 9-11, many biometric fingerprint systems instantly declared that they were the new vanguard for detecting terrorists, despite nonconformity with law enforcement AFIS to enable import and comparison of suspects’ fingerprints… despite the absence of fingerprint hardware that captured rolled fingerprints at the correct pixel per inch resolution… and despite the absence of fingerprint recording devices (platens) that could capture four simultaneous fingerprints for sequence verification required by all law enforcement AFIS systems. 

After 9-11, agencies like the Immigration and Naturalization Service (now part of the Department of Homeland Security or DHS) immediately began beefing-up biometric systems used at borders to fill the gaps between that technology and law enforcement AFIS.  DHS employs well-qualified forensic fingerprint experts (Latent Print Examiners) who effect identifications impossible using only "lights-out" biometric technology. 

However, some other agencies without law enforcement fingerprint experience or expertise (those agencies who failed to research standards always prominently posted by organizations such as OSAC and Interpol) may have been fooled by biometric vendors into thinking that they were adopting electronic fingerprint systems that were as accurate and robust at detecting terrorists via fingerprints as law enforcement AFIS.  Some activities have captured tens of thousands of persons' fingerprints in nonstandard formats presenting tremendous problems for vetting against law enforcement AFIS collections of known and suspected terrorists and other criminals. 

A large federal laboratory like the FBI or Army Crime Laboratory may only search somewhere in the neighborhood of 100,000 to 250,000 (these are estimates) single fingerprints per year against the FBI's national AFIS (NGI).  Thus, searching a collection of tens of thousands of nonstandard fingerprint records as latent print searches is a monumental task. 

Because nonstandard biometric systems cannot accept law enforcement standard rolled fingerprint records, the internal comparisons in such systems are often not very meaningful insofar as detecting persons on law enforcement/terrorism watch lists.  The most wanted terrorist in the world could register in the system easily just by giving a false name.  He is then known in that system under the false identity.  He is free to plan attacks on the facility using information learned while he was permitted inside.  Isolated biometric systems incapable of interfacing with law enforcement AFIS give a false sense of security insofar as vetting against the thousands of known and suspected terrorists' fingerprints the US government has on file in law enforcement AFIS networks. 
 
Also, non-law enforcement standard electronic fingerprints complicate (and in most biometric systems preclude) comparison against latent prints harvested from bombs and other terrorism-related evidence.  Department of Homeland Security, the FBI and US military biometric support activities have created specialized systems that increase the ability to utilize nonstandard fingerprints for conventional law enforcement type comparisons... and some great successes have occurred to identify latent fingerprints and record fingerprints of criminals, including known and suspected terrorists' fingerprints on bombs and other important evidence.

Biometrics is the system you will use in prison so you can get back in from the exercise yard or go to the cafeteria.

AFIS is the system which helps put you in prison.