Which method was NOT a feature of policing changes from 1900 to 1940?

The correct answer highlights that the use of personal communication devices was not a feature of policing changes from 1900 to 1940. During this period, police departments were undergoing significant modernization, which included several innovations aimed at improving efficiency and effectiveness in law enforcement.

The deployment of radio communication systems, for instance, revolutionized the way officers communicated, permitting instant updates and coordination, which was a major leap from previous methods. Rapid response capabilities emerged as departments adopted these radio systems, allowing for faster attendance at incidents. Additionally, the introduction of vehicle patrols fundamentally changed policing strategies, enabling more extensive coverage of areas and enhanced response times to crimes and emergencies.

In contrast, personal communication devices as we think of them today—such as mobile phones—were not yet in existence or utilized within policing practices during this time frame. Instead, police relied on traditional means of communication, which were often slow and limited in scope. This distinction makes it clear that personal communication devices were not a feature of policing in that era, setting the correct answer apart from the others, which were indeed pivotal changes in policing methods during those decades.