In which phase is the decision to arrest typically made?

The decision to arrest is typically made during Phase Three of the Horizontal Gaze Nystagmus (HGN) test. At this stage, the officer has already completed the initial observations and has engaged with the suspect through various testing phases. By the time the officer reaches Phase Three, they have gathered sufficient evidence from the prior phases, including the preliminary assessment of the suspect’s behavior and any indicators of impairment observed during the tests.

Phase Three focuses on the actual decision-making process where the officer evaluates the totality of circumstances. This includes interpreting the results of the HGN test, assessing the suspect's performance in field sobriety tests, and considering any other signs of intoxication. The culmination of these observations allows the officer to make an informed choice regarding whether or not to proceed with an arrest for driving under the influence (DUI).

Understanding when this decision is made is crucial because it emphasizes the importance of systematic evaluation and the need for officers to rely on the comprehensive information gathered throughout the testing phases before making a determination about an arrest.