A biometric sensor may be coupled to a portable communications device, such as a cellular telephone. The biometric sensor may be configured to acquire one or more measurements of biological characteristics of an individual. One or more of the measurements may relate to internal, sub-epidermal characteristics of the individual, such as non-volitional processes occurring within the individual, sub-epidermal structures within the individual, or the like. A biometric marker may be derived from one or more of the measurements. The portable communications device may be activated responsive to deriving the biometric marker. The activation may include transmitting the measurements and/or biometric markers derived therefrom to a receiver using the portable communications device.