Disclosed techniques relate to identifying subjects in digital images. In various embodiments, a first camera (276, 376, 476, 976) may acquire (1002) digital images (420) depicting a subject in an area. Portion(s) of the digital image(s) that depict a face of the subject may be detected (1004) as detected face image(s). Features of the detected face image(s) may be compared (1006) with features of subject reference templates associated with subject(s) in a subject reference database (412). The subject reference database stores subject reference templates that are associated with multiple subjects and that are generated based on data received from a second camera (256, 456). Based on the comparing, an identity of the subject may be determined (1014) and the features of the detected face image(s) may be stored (1016) in the subject reference database in association with the subject, e.g., as an auxiliary template feature vector for later use.