Biometrics is the measurement of the biological, physiological, and behavioral characteristics of an individual. Biometric technology can be used by law enforcement agencies to facilitate criminal investigations and many biometric applications are already in use by police. Several types of biometrics used by law enforcement are reviewed in this report including facial recognition; fingerprint and hand geometry; iris, retina, and voice recognition; as well as biometric applications that measure gait, heart, and brain waves. Smartcard technology that allows encrypted biometric information of individuals to be stored in a smartcard for quick identification is also described. Privacy concerns have been raised regarding the use of biometrics, among them are concerns about biometric revealing more than is known, such as information on temperament and mood. Finally, the report develops a perspective regarding the use of biometrics by the police. Four main recommendations guide the law enforcement use of biometrics: (1) police should pursue advancements in facial recognition and fingerprint biometrics for purposes of criminal investigations; (2) a marketing strategy should be developed to extol the benefits of new biometric technologies to ensuring the public safety; (3) police and other related agencies should promote standardization in biometrics technology and practices; and (4) police should consider the ability of technology providers to provide long-term maintenance and equipment upgrades. Figures, table, references, appendix