The study used police contact data from the juvenile offense portion of the 1958 Philadelphia birth cohort. Analysis was based on the assumption that police use type-script (and countertype) heuristics based on suspects' race, gender, socioeconomic status (SES) and offense type to assist in their arrest decisions. Logistic regression analyses on arrest decisions for offenses categorized according to their gender type-script showed that, in the aggregate and when other variables were controlled, females were less likely to be arrested and that race and SES also significantly affected the arrest decision. Among all offenses, the gender-typing variable explained a large portion of the effect of gender alone on the arrest decision. Within gender-type offense categories, officers considered offense seriousness and, most notably, the number of prior police contacts in arrest decisions, a factor of slightly more significance in decisions regarding females. Results were confounded by interactions with race and SES. Notes, tables, references