Biometrics is the means for uniquely recognizing humans based upon one or more intrinsic physical or behavioral traits. (Wikipedia) This recognition or identification can be used as a system for cataloging or, more specifically, storing and comparing information on individuals. The system must first store an individual’s information, which will later be used to compare and verify.

Biometric systems are based on matching or verifying at the point of interaction. Individuals will submit a scan of a "live" sample, which will then be stored in the system. The most common types of biometric solutions are being used for security. So for example, at security points, the identification will take place by verifying the person against their sample. These samples are based on unique characteristics of an individual for the purpose of identifying. The most typical biometric security systems in correctional facilities are using identification based on the thumbprint, iris scans, voiceprints and to some extent radio-frequency identification (RFID).

As technology evolves and more and more Requests for Proposals (RFPs) go out to bid, the question of biometrics starts to play a bigger role. What types of biometrics make sense for the correctional industry – what are they, what works, and which ones are worth the cost?

Fingerprints or thumbprints are the oldest and the most commonly known biometric. This biometric identifier has been utilized for identifying perpetrators by law enforcement for decades. Fingerprints are unique and, barring injury, remain consistent throughout life. As we know, the patterns of ridges and valleys on an individual’s fingertips are unique to that individual, even to identical twins. Law enforcement classifies and determines identity by matching key points of these ridges and valleys. Fingerprints are captured, digitized into mathematical descriptions, and compared by computers against known and unknown or latent fingerprint databases. Sensors can reliably authenticate the identity of a user in approximately one second.

While efficient, employing thumbprint biometrics within jails and prisons requires this system to be integrated with the Jail Management System. This may be cost prohibitive depending on the solution and, of course, it isn’t fail-safe since inmates can forcibly use another inmate’s thumb to bypass the system. Additionally, when fingerprint scanners are attached to inmate telephones, the devices can be easily damaged by inmates and may then render the phone ineffective, thus limiting communication between inmates and their loved ones. Calling can be even further limited because injury, dirt, and calluses can affect the technology’s ability to positively identify an inmate.

Iris Scan

Comparing irises against a database can be done quickly and with a high level of accuracy. The technology is not intrusive on the individual (unlike older techniques that scanned the inner blood vessels of the retina) and can be used even in the presence of eyeglasses and contact lenses. Research suggests that a person’s retina can change with age, while an iris remains intact, and usually people’s eyes remain unchanged even after eye surgery. Blind people can use iris scanners as long as their eyes have irises. Iris recognition has also been demonstrated to work with individuals from different ethnic groups and nationalities. However, for people affected with diabetes, the eyes sometimes are affected by the disease, resulting in changes to the iris.

Iris scanning devices have been used in personal authentication applications for several years. Systems based on iris recognition have substantially decreased in price, and this trend is expected to continue. Because iris scanning is quick and highly accurate, it is particularly effective for perimeter and access control. Iris scanning is becoming more popular in correctional facilities as well – several facilities, including Lancaster County and York County prisons in Pennsylvania and Sarasota County Detention Center in Florida, use iris scanning technology as part of their release procedures. (Allen Turner, Biometrics in Corrections, July 2003) In Sarasota County, the iris scans are used to prevent former prisoners from visiting former inmate pals. (TechBeat, Fall 2000 edition) Iris scanners are already in use in airports and other secure facilities, including use for immigration and customs clearances.

The voice is another unique identifier, this one based on the shape of an individual’s vocal cavities and on the way an individual’s mouth moves with speech. With voice recognition, the voice itself -- its tone and timbre -- is the password. The technology is used to authenticate identity through digital comparison of that voice against a database. In a voiceprint system, an individual gives an extended sample of speech so that the computer can identify the individual’s voice in the future, no matter which words are spoken. Voiceprint can capture multiple voice imprints from an individual to use as identifiers.

For example, using voiceprint with an inmate telephone system, the inmate’s voice is recorded at the time of booking. The voice is then verified each time the inmate places a telephone call – this is usually used in combination with PINs.

Voiceprint biometrics, while unique, has some inherent flaws. It is found that with age, the voice of a person changes. Additionally, when a person has the flu or a throat infection, the voice is affected; and there are challenges when there is too much environmental noise, which may interfere with accurate authentication. This is especially true in a prison setting. There also may be a difference between an inmate’s voice when they are booked and later, when they attempt to use the telephone. Sometimes inmates are booked while under the influence of drugs or alcohol, or they are under duress, and their voice may sound different later when placing a phone call. For these reasons, this method of verification is not workable all the time.

RFID

RFID, or radio-frequency identification, is a system that relies on a "tag." An RFID tag is an object that can be applied to or incorporated into a product, animal, or person for the purpose of identification and tracking by using radio waves. Since the device does not require any biometric input, such as voice, eye, or fingerprint, it is not a biometric feature in the true sense of the word. However, the device is used for the same purpose – correctly identifying an individual.

Most RFID tags contain at least two parts: (1) a decoder to interpret the data; and (2) an antenna for receiving and transmitting the signal. Not unlike the product barcodes utilized in supermarkets, RFID is commonly used in improving the efficiency of tracking. The advantage of RFID is that it does not require direct contact or line-of-sight scanning; some tags can be read from several meters away.

RFID tags are currently being utilized in correctional facilities with inmate wristbands as a means of tracking and identifying inmates. A bracelet is worn on the wrist that is equipped with an RFID tag and an antenna that wraps around the entire wristband; this prevents it from being cut or reused by any other inmate. Unfortunately, this technology isn’t fail-safe, either. Inmates can forcibly use another inmate’s wristband to bypass it. Some systems, however, work to ensure that one and only one inmate can actually use the wristband. For example, when an inmate uses a phone, the reader constantly scans the wristband during the phone conversation and measures the distance from the phone that an inmate is actually standing. If the wristband is more than about 6" from the reader, a warning is provided, and the call is disconnected.

Although their use is somewhat limited and no single measurement works for everyone, biometric identification technologies hold substantial promise for corrections and law enforcement. Biometrics in correctional facilities has not yet been fully realized due in part to lack of knowledge in its application, as well as the relative newness of the technologies. As with many interesting and powerful developments of technology, there are some concerns about biometrics – compromised data, costs, equipment durability, accuracy, and reliability, as well as integration into a current system – which make it important when choosing a biometrics system to match it to the unique correctional environment.

What works well in a laboratory may not work as well in the actual world, and some systems may work better in some environments than others. Once a biometric source (thumbprint, voiceprint, etc.) has been compromised, it is compromised for life – users can never change their unique identifier. Biometric equipment is environmentally dependent; for example, heat or sound may disrupt the accuracy of readings. Equipment durability is also an issue, especially for correctional facilities with high volumes of use. And there is the increased potential for deliberate vandalism by inmates, who are likely to damage equipment designed to track their movements.

Today the costs of biometric technology are still high, both in terms of money and staff time required to use them effectively. It is an expensive security solution because it can be cost prohibitive to manage all the components, not to mention all the upfront deployment costs. The accuracy and cost of the system plays a big role in whether or not to integrate it into the current jail system. The ability of a biometrics system to seamlessly integrate into the information and tracking systems already in place is a concern for correctional facilities. Additionally, accuracy and reliability of biometrics technologies will have to mature before they will be implemented on a larger scale by more correctional facilities.

So, the next time a vendor offers you the latest biometric technology, determine what this biometric system is supposed to do and where and when it should do it. Next, take into account your particular needs in terms of security, policy, and practicality. For example an iris or fingerprint scan may be appropriate in a "super max" environment, a PIN and voice recognition combination in a medium security facility, and a PIN alone in a minimum security facility. Lastly, determine whether the system will actually aid in efficiency without compromising your revenues and budget.

PCS constantly monitors and anticipates developments in biometrics within the banking and security industries, and we are confident that our research will eventually lead to major opportunities for economical application of some of these technologies in the corrections environment. PCS will report on these developments as they arise.