Drunk Driving - Anatomy of an Investigation

Driving While Under the Influence

When determining if someone is “under the influence” the jury can consider the person's driving, mannerisms, speech, appearance, emotional state, performance of field sobriety exercises, and anything else that may play a part in the above factors.  Police officers are taught to observe and document everything they witness about an individual from the time they come into contact with the vehicle to the time they turn them over to jail staff if an arrest is made.  A drunk driving investigation really has three primary stages from a police officer’s perspective. 

Stage 1:  Vehicle In Motion

The officer is watching a vehicle to determine if there is a sufficient basis to pull it over.  For alcohol related investigations, officers are specifically trained to look for things such as weaving, inconsistent actions such as slowing down and speeding up or signaling one way but turning another, or failing to use headlights.  They also pay close attention to how a person reacts to being pulled over.  Officers document whether or not the person does not immediately pull over, whether they hit the curb, fail to signal, or even pull over too abruptly.  Obviously, from the defense perspective, anything the person did correctly will also be highlighted to combat the officer’s claim that the person was intoxicated.

Stage 2:  Personal Contact

At this stage of the investigation, the officer makes personal contact with the driver of the vehicle asking for license, registration and proof of insurance.  One game officers like to play is to ask for multiple items at one time and while the person is retrieving those items, to ask them questions about where they are coming from and what they have been up to that evening.  Law enforcement calls this a “divided attention task.”  According to their theories, intoxicated individuals will have difficulty providing these items and answering questions at the same time.  Other reasonable explanations would obviously be nerves, cluttered glove box, or a normal lack of attentiveness.  Again, anything the person does correctly will be highlighted as evidence of sobriety.  During this stage, the officer will also question the driver about whether or not they had consumed any alcohol and where they were coming from and where they were going.  They also pay close attention to the driver’s eyes, breath and speech.  Almost every officer’s report will claim that the arrested person had “bloodshot and watery eyes, slurred speech, and an odor of an alcoholic beverage coming from their person or breath” whether they really made those observations or not.

Stage 3: Pre-Arrest Screening

These are commonly referred to as field sobriety exercises.  At this stage of the investigation, the officer has already determined that they suspect the person has consumed alcohol and claims to simply want to determine if the person is “ok to drive.”  The normal statement from the officer is: “since you told me that you have been drinking, would you mind doing a few quick tests to make sure you are ok to drive?”  If the person agrees, they are run through three “standardized field sobriety exercises”:  1) Horizontal Gaze Nystagmus; 2) Walk and Turn; and 3) One Leg Stand.  These three “tests” are usually followed by a preliminary breath test.

Officers and ultimately the prosecution will pick apart everything and anything the person does in order to make them out to be a stumbling drunk.  As you can see, from the minute a person comes into contact with the officer, every movement and statement is being scrutinized.  This is why it is important to have an attorney who knows and understands what the officers look for so that their own investigation techniques can be used against them to provide evidence of sobriety.

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