When a Montana police officer believes a driver may be under the influence of drugs or alcohol, the officer may administer preliminary screening tests. These tests include field sobriety tests and preliminary breath tests. They are designed to help an officer determine whether a driver is operating a motor vehicle under the influence of drugs or alcohol and therefore should be arrested. Field sobriety tests typically include the walk-and-turn test, the one-leg stand test, and the horizontal gaze nystagmus test. The National Highway Traffic and Safety Administration provides training to police officers to teach them how to administer these tests properly. The walk-and-turn test requires a driver to take several steps, heel-to-toe, turn around, and return in the same manner. The one-leg stand requires a driver to hold one foot off the ground while counting. In both of these tests, the officer is looking for indicators that the driver is having difficulty performing a mental exercise at the same time as a physical one. The horizontal nystagmus test requires a driver to track a moving object visually. In this test, the officer is watching the smoothness with which the driver can track the object. The next test usually requested by an officer will be a Preliminary Alcohol Screening Test, also known as a Preliminary Breath Test. This small, portable breath testing unit has a number of known flaws, and as such, its use it usually limited to assisting the officer in determining whether to arrest a suspect. However, Montana Courts have, under extremely rare and limited circumstances, allowed a Preliminary Alcohol Screening Test to be used a substantive evidence of guilt at a trial. At Tipp & Buley, we have over 55 years of collective experience in dealing aggressively with DUI charges brought against Montana drivers. We have been trained on breath testing devices and are active in teaching others how to defend DUI cases. If you've been charged with DUI in Montana, put our experience to work for you: Call us today at 406-549-5186 to set up a one-on-one consultation.
Preliminary Screening Tests: What Are They and How Are They Used in Montana DUI Cases?