We tested developmental trends in eyewitness identification in biased and unbiased lineups. Our main interest was adolescent's lineup performance compared with children and adults. 7-10-year-olds, 11-13-year-olds, 14-16-year-olds, and adults (N = 431) watched a wallet-theft-video and subsequently identified the thief, victim, and witness from simultaneous target-present and target-absent six-person photo lineups. The thief-absent lineup included a bystander previously seen in thief proximity. Research on unconscious transference suggested a selection bias toward the bystander in adults and 11-13-year-olds, but not in younger children. Confirming our hypothesis, adolescents were more prone to bystander bias than all other age groups. This may be due to adolescents making more inferential errors than children, as predicted by fuzzy-trace theory and associative-activation theory, combined with lower inhibition control in adolescents compared with adults. We also replicated a clothing bias for all age groups and age-related performance differences in our unbiased lineups. Consistent with previous findings, participants were generally overconfident in their decisions, even though confidence was a better predictor of accuracy in older compared with younger participants. With this study, we show that adolescents have an increased tendency to misidentify an innocent bystander. Continued efforts are needed to disentangle how adolescents in comparison to other age groups perform in forensically relevant situations.