Livingston Detective Practice Test - Prep, Practice Questions & Study Guide

The defining characteristic of a reactive response in investigation modes is that it involves responding to crimes that have already occurred. In this context, a reactive response typically comes into play after a crime has been reported or discovered. Investigators or law enforcement officials act on existing evidence and information to understand the details surrounding the event, gather information from witnesses, and identify suspects based on the situation at hand.

In contrast, proactive planning focuses on preventing future crimes before they happen, which distinguishes it from reactive approaches. Investigating potential criminal activity and collecting data from various subjects also fall outside the scope of a reactive response, as those efforts are oriented towards anticipating criminal acts rather than responding to past incidents. Thus, the essence of a reactive response lies in addressing and investigating events that have already transpired, making the correct choice about responding to crimes that have already occurred.