When citizens are pulled over by police for traffic violations, they often volunteer accounts for their driving conduct. These accounts convey important character qualities about the citizen, as well as exigencies that motivate officer response. We use the method of conversation analysis to show that where a citizen positions an account in the course of an encounter is subject to different interactional-organizational constraints, which in turn afford citizens different resources for self-presentation. We also show that officers are sensitive to citizens’ (...) accounts and respond to them in differentiated ways. In addition to being a resource for self-presentation, citizens’ volunteered accounts are a resource for motivating and shaping police action. (shrink)