Legal Issues Arising from the Military Use of AI-Supported Biometrics

Biometrics is increasingly used by armed forces for a variety of purposes, such as access control, the registration of detainees, and increasingly also targeting. The capabilities of biometric systems are considerably strengthened when they are enabled by artificial intelligence (AI). This article analyzes legal questions that are raised by the military use of such AI-supported biometrics. It argues that relevant legal frameworks are International Humanitarian Law, international human rights law, and the right to privacy in particular, as well as data protection law. The article finds that arguably, IHL may require the use of (AI-supported) biometrics in certain situations if this capability is available. This legal regime as well as the other two contain rules and principles that limit certain uses of AI-supported biometrics in certain cases and that require certain safeguards to be put in place. In many cases such requirements can be based on more than one legal regime, suggesting that the regimes are largely complementary. Requirements flowing from the three legal regimes apply throughout the entire "biometric cycle," from the design and development of a biometric system to its actual use in the field. An important finding is that during the design and development of a biometric system and at the stage of decision-making concerning its deployment, applicable law requires taking into account particular risks and taking measures to mitigate these risks.