As a former police officer, I will admit that on a really slow night, the police are looking for any reason to pull someone over. I have stopped cars for the license plate light not working, having items hanging from the rear view mirror, cutting through a parking lot to avoid a traffic light, and even having a license plate frame that covers the state name, no matter how slight. The motor vehicle code is thick; it doesn’t take much to find a reason to stop someone.
Now imagine you get behind the wheel of your car after having consumed 6 beers. You pull onto the road and, almost immediately, you’re pulled over by the police. Long story short, the officer smells alcohol on your breath and asks you to perform some field sobriety tests. You comply, you fail miserably, and he places you under arrest for Operating Under the Influence (OUI/DUI or drunk driving).
When a client comes into my office, I ask a lot of questions about the initial motor vehicle stop. This is because if I can show that the officer could not have had articulable suspicion to stop the car (no matter what the reason he gives for stopping your car), then the exclusionary rule says that any evidence gathered afterwards is also inadmissible. Bear in mind that there are several exceptions to the exclusionary rule, and this is by no means the only defense to be looking at, but it is the first that I like to consider. For example, assume that it can be shown that the purpose behind the stop was based upon racial profiling (it’s easier to explain by going to the extreme). Selective enforcement is a violation of the equal protection clause of the Massachusetts Declaration of Rights. So the stop was illegal. Because the stop was illegal, all other evidence gathered as a result of the stop is “fruit of the poisonous tree.”
There are many defenses available to someone who has been arrested for drunk driving. The exclusionary rule is only one of those defenses. It’s not a defense that can be used in many cases, but I like to consider it at the beginning of each case. You never know when it can work in your favor.