Biometrics
Biometrics refers to the measurement of specific physical or behavioral characteristics and the use of that data in identifying subjects. With wide application, biometric-based identification techniques are increasingly an important part of forensic science investigations because biometric data is difficult, if not impossible, to duplicate or otherwise falsify. Examples of such data include retinal or iris scans, fingerprints, hand geometry, and facial features. Accordingly, biometric systems offer highly accurate means of comparison of measured characteristics to those in a preassembled database.
Biometric identification points include gross morphological appearance that is most often subjectively interpreted upon superficial examination (e.g., gender, race or color of skin, hair, and eye color). Other gross biometric data can include more quantifiable—and therefore less subjective—data (e.g., weight, height, location of scars or other visible physical markings). Some biometric data is easily changeable and therefore not reliable (e.g. presence of facial hair, wearing of glasses, etc.).
Because even objective features such as weight can change over time, systems of identification that rely on changeable or gross features are not as reliable as biometric systems that measure more stable anatomical and physiological characteristics such as fingerprints, retinal blood vessel patterns, specific skull dimensions, dental and skeletal x rays, earlobe capillary patterns, and hand geometry.
The most specific and reliable of biometric data is obtained from DNA sequencing.
More controversial and, at present, less reliable biometric studies seek to enhance quantification of social behaviors, voice characteristics—including language use patterns and accents—handwriting, and even keystroke inputs patterns.
Biometric data can be encoded into magnetic stripes, bar codes, and integrated circuit "smart" cards.
On a global scale, biometric data interchange and interoperability standards are at present fragmented into different measurement and input format schemes. The Common Biometric Exchange File Format (CBEFF), in development by the International Biometric Industry Association (IBIA), seeks to integrate such measurement schemes to enhance reliability and use of biometric data. Other integration efforts include the Biometric Application Programming Interface (BioAPI) specification program used by the United States Department of Defense. The Department of Defense has also established a Biometrics Management Office (BMO). BioAPI protocols are also being used by other governmental agencies and the financial service industry in the development of smart cards.
The National Institute of Standards and Technology (NIST) also dedicates programs to biometric research and exchange. NIST developed the initial data protocols used in the Face Recognition Vendor Test (FRVT) and established the format for data collection used by most face recognition technologies.
Finally, reflecting the power of biometrics in forensic science, police forces are increasingly equipping themselves with the technical and personnel expertise to undertaken biometric examinations. These efforts are aided by the Internet, which allows police forces to access databases and share information on a global scale.
