Subjects included 87 men and 46 women stopped by four officers. The degree of nonverbal aggression was reported on a mood scale by the 133 citizens halted for an information check (neutral condition) or for a traffic ticket (negative condition). Results indicated that subjects in the negative condition both expressed and reported more aggressive feelings when the police officer wore a weapon than when no weapon was visible. The use of sunglasses had no effect on aggressive feelings but resulted in the officers' being perceived more negatively, though they were not perceived more negatively when they wore a weapon. No sex differences in expressed or reported aggressiveness were obtained, although some sex differences on measures of secondary interest occurred. Implications of the research findings are discussed. Figures and 20 references are provided. (Author abstract modified)