Data were obtained from police and criminal prosecution files and banking association statistical reports for the study period. The highest percentage of cases occurred in communities of less than 5,000 population, and most robberies occurred in the winter, with Thursdays and Fridays most often chosen for the robberies. The number of robberies accomplished in 3 minutes or less (87.3 percent) has doubled since earlier studies. Despite the increase in bank robberies, the rate of cleared cases has remained constant. An effective technological security system, especially the use of optical surveillance, has contributed to successful case investigations. Escalation in the robbers' behaviors to circumvent the 'neutralizing' effects or obstacles of technological prevention is the only apparent negative consequence of increased technological security. This escalation of criminal behavior to compensate for improved bank security has not occurred on a wide scale, and it consists primarily of the temporary taking of a hostage.