In Missouri, law enforcement officers are governed and regulated by the National Highway Traffic Safety Administration’s (NHTSA) protocol when conducting field sobriety tests and making DWI arrests. Since 1984, the Missouri police academies have been teaching the NHTSA-based course on DWI detection and standardized field sobriety testing.
The process of detecting drunk drivers begins when a police officer suspects that a potential driving while intoxicated or driving while under the influence offense may be occurring. All conduct that occurs from the police officer’s first observation of a driver and through the arrest of a driver is governed by NHTSA protocol.
There are three phases of DWI detection for Missouri drunk driving cases under the NHTSA standards.
Vehicle in Motion – Phase one of the DWI detection process begins when an officer first observes the driver while operating the vehicle. In some cases, such as accident-related cases, this component in the DWI detection process may not be applicable. When phase one applies, the officer is required to observe clues regarding the vehicle in motion and the driver’s stopping sequence. The officer will look for visual clues to use and record while observing the vehicle in motion. Some common clues may include straddling the center lane or lane marker, turning with a wide radius, weaving, swerving, nearly striking an object, drifting, braking erratically, among many other clues. The second component of observing the vehicle in motion requires the officer to observe the manner in which the driver responds to the signal to stop. An officer will look for clues such as the driver not responding, the driver being slow to respond, the driver coming to a sudden stop, among others.
Personal Contact With Driver – The second phase in the DWI detection process requires the officer to observe and interview the driver, and to observe the driver’s exit and walk when the driver is asked to step from the vehicle. Under NHTSA guidelines, the officer is to observe what he sees as he approaches the vehicle, what he sees, smells, and hears when speaking with the driver, and how the driver exits the vehicle and walks toward the side of the road. Under NHTSA protocol, it suggests that an officer give divided attention tasks to a driver to see if he or she can successfully complete them. For example, asking for a driver to produce his or her driver’s license and vehicle registration is a divided attention task because it requires two requests.
Pre-Arrest Screening – Phase three of the DWI detection and arrest process has two major components to it. The first component to phase three is the standardized field sobriety test, which typically includes the horizontal gaze nystagmus test, the walk-and-turn test, and the one-leg stand test. If sufficient probable cause exists to arrest the driver based on his or her performance on the field sobriety tests, the officer may then ask the driver to submit to a portable breath test.
At Henderson Law Group, we handle cases ranging from a first-time DWI offense to felony DWI cases throughout Missouri and Illinois. Our experienced DWI lawyers understand this complex area of law, and know what steps to take to protect your rights. We will work tirelessly to obtain the best possible result for you. Contact us today for a free consultation. We are available 24 hours a day, 7 days a week.