What Is AFIS and Why Is It Important to You and I?

(A) stands for automation. In the old days a person use to have to compare two cards with fingerprints on them to know if they match. This “old” card system is being replaced with an automated system that can compare a lot fast and do a lot more than one person could ever handle at one time.

(F) stands for Fingerprint. The fingerprint image can be captured using a card or a device that is a close cousin to a scanner. All fingerprints will eventually have to be in electronic format for the automated part to work, so cards will be scanned in.

(I) stands for identification. Someone is identified when a fingerprint image is matched up to an image in the database. I say images, but as far as matching goes usually there is much less information saved in the database then an actual image. There are characteristics of fingerprints that can be saved and searched on much faster than an actual image.

(S) stands for system. This system is made up of computer and software. This can include scanning stations, review stations. There are a lot of different components that work together to identify fingerprints in the AFIS.

What is AFIS?

These systems are used mostly for law enforcement agencies and can be extremely large systems. The largest of the AFIS holds hundreds of millions of fingerprints and can find matches within seconds. For this kind of processing power the systems can end up being somewhat complex.

Many agencies may band together to make one large AFIS that can be used by many people at once. This helps cut down on costs for each agency and makes for a much bigger and better system than if each agency set out to build their own AFIS. Most agencies will also network in other systems to add to the efficiency and chances of finding a match.

As time goes by the AFIS are getting faster and faster and matching algorithms get more advanced and better as companies learn more and develop better systems.

Why is fingerprinting such an important aspect of identification? The most important feature of a fingerprint is that a fingerprint is unique throughout the world. In other words, there are no other fingerprints exactly like the ones on your fingers. Even though not all the people in the world are in a fingerprinting system, even the largest system has no two fingerprints that are exactly the same. This makes it an ideal biometric (meaning a feature of your body) because it can uniquely identify a single person.

Along with just the finger tips there are other prints being added into AFIS, prints from palms and sides of the hand are being added.

Eventually there will be other biometrics that will be added to this vast ocean of fingerprinting information. Iris and Facial recognition to name two. DNA may even be used to identify individuals, especially since DNA is also another aspect of the human body that would be unique for each individual on the planet.

You might wonder how AFIS works. Comparing images would be ineffective and tedious, even for a computer. Perhaps some day comparing images will make sense, but computers are not quite up to the task because of speed and band-width limitations. So, what is used to compare and match fingerprints? Usually, it’s just characteristics of a fingerprint that are matched. This includes points where ridges end, points where ridges split, direction that ridges are placed and even dots. Selected key features are chosen on the fingerprint as minutia points (about 200 of these are formed for a rolled fingerprint. Obviously, the more the better). It’s these minutia that are matched against to find the best match for a chosen fingerprint by AFIS.

Luckily, the computer never has the final say on a fingerprint match. There usually has to be an examiner near the end of the matching process to double-check the computer and make sure it is really a match. At this time there’s no substitute for a good examiner when it comes to deciding if two fingerprints are a match.

After a match is found usually the agency that requested the fingerprint search will receive a full disclosure of the identity of the person (called a rap sheet). This can all happen in less than 30 minutes. With the new FBI system IAFIS this time can be dramatically shortened.

AFIS is getting faster all the time, so the time taken for a search will get shorter and shorter.

Why is AFIS important to you and me?

If you are a criminal you may be more familiar with AFIS than you care to be. If you are not a criminal then you may be wondering what AFIS has to do with you? Since fingerprints are such an easy biometric to capture fingerprinting is finding more and more applications in everyday lives of people, outside of legal matters.

For example fingerprinting machines can be used to give access to areas that need to be secure, like a government facility, a lab, dangerous areas where someone who is unfamiliar with what’s behind the door could get hurt, or even your own front door. Fingerprinting can work much better than doorknob that has to have a key. The person wanting access carries the key to the door with them all the time. It eliminates the need for someone to “remember their keys”. Their fingers stay on their bodies.

A Flaw of Fingerprinting

Security brings up other interesting topics. Because fingers can be removed or faked, there are still alternative methods being developed. If fingerprinting was fool-proof there would be no need for any other biometric to be on record.

We’ve all seen the movie where the guard gets his hand or finger removed and the criminal uses the taken appendage to get into restricted areas.

Protect your property

Most people don’t realize that their fingerprints are their property and to give them out to anyone who asks for them may be like giving them your favorite toy and never seeing it again. The problem with a fingerprint is it could well be used against you, which is why you should always be careful about who you give it to. Make sure you’re doing it for a good and fair reason. For example, you got a job where they require you to place your finger on a finger reading machine to enter into the building where you work. This seems like fair compensation for entry into your place of employment.

Most people don’t think about giving away their fingerprints. This article just recommends caution, not paranoia.

The Future of Fingerprinting

The future of AFIS will be a machine where a person will walk through and it will retrieve all biometric information, fingerprints, facial, iris and you won’t really have to do anything, just walk through it.

A machine like this would have a direct application in an airport. This machine would identify someone and then search a database for known terrorist and decide all kinds of things about the person before they even get to the end of the walking area. This would stop a known terrorist or some other dangerous person from getting on a plane and causing problems for a lot of people.

This same machine could also check out people for dangerous or explosive devices on their person, or any other information the controllers of the machine cared to collect.


AFIS is an exciting field of study. It is a field dominated by few companies and individuals because of the high level of technical knowledge that is required to build such a system. It’s not for the lazy or the faint-hearted. For further study check out the book “Automated Fingerprint Identification Systems (AFIS) by Peter Komarinski. And, remember what mom use to say all the time, “keep your hands to yourself!”