The Three Phases of DUI "Detection"
Contrary to public belief, it is not illegal to drink and drive. It is illegal to drive while under the influence of alcohol, drive while inoxicated, drive while impaired, or drive in a condition that your state says is illegal. Believe it or not, police officers are trained to recognize when a driver is in that condition. Now, before I get too far, I want to point out that I am a DUI attorney in Maryland, Virginia, and DC. But this is not legal advice. It is purely information, and is not specific to any situation. If you need legal advice or professional assistance for your own situation, then you should contact an attorney that is licensed in your state.
For purposes of uniformity, through this article I will use the abbreviation "DWI", but you could easily substitute "DUI", "OUI" or "OWI". Police officers are trained to divide DWI detection into three phases: vehicle in motion, personal contact, and pre-arrest screening.
1) Phase 1: Vehicle in Motion.
In phase 1, the police officer is trying to answer the question of whether to stop the vehicle. It begins with the initial observation of the vehicle and the manner in which it is being driven.
2) Phase 2: Personal Contact.
In phase 2, the police officer is trying to answer the question of whether to ask the driver to exit the vehicle. It begins with the initial contact with the driver and the observations of the police officer. During the personal contact phase, there is an opportunity for the officer to observe and speak with the driver.
3) Phase 3: Pre-Arrest Screening.
In phase 3, the police officer is trying to answer the question of whether there is probable cause to arrest the driver for DWI. The bulk of the pre-arrest screening is the field sobriety tests. The National Highway Traffic Safety Administration, a division of the Department of Transportation, recognizes three standardized field sobriety tests: the horizontal gaze nystagmus test, the walk and turn test, and the one leg stand test. Additionally, officers often administrator a preliminary breath test or other non-standardized field sobriety tests.
Throughout the three Phases, the police officer is trained to look for certain clues that increase the likelihood that the driver is impaired. The officer is also trained to include each clue in a police report. Sometimes, all three Phases are not present in a particular DWI stop. For example, if there is a collision involved or the stop took place at a roadblock, one or more of the sentences may be absent.
Of course, the next logical question becomes what to do when armed with this information. That is what your DUI attorney is for – to use this knowledge and any other evidence to assemble your best defense.