What should be checked in the driver’s mouth before the observation period begins?

Before the observation period begins during a DUI traffic stop, it is crucial to check the driver’s mouth for foreign objects. This step is essential because any foreign object could potentially interfere with the results of a breathalyzer test, leading to inaccurate readings. For instance, if there are remnants of food or other non-airborne substances in the mouth, it may introduce substances that can affect the breath sample. The goal of this check is to ensure the integrity of the breath sample collected later, as any foreign materials could result in misleading evidence regarding the driver’s level of intoxication.

While medications, food items, and dental work can also be relevant factors during a DUI investigation, they are not the primary focus of the initial check of the mouth. Medications could affect a person's behavior or level of impairment, but they do not directly interfere with the breathalyzer test as foreign objects do. Food items can certainly affect breath tests if they are not cleared before testing, but the immediate priority is to ensure there are no foreign items that impede an accurate assessment. Dental work may be considered during the investigation as it could affect the driver's physiology or breath sample, but checking for foreign objects is the most critical first step before commencing the observation period.