I consider myself a student of human nature. Understanding human tendencies is very helpful to a lawyer for many reasons. Besides, I enjoy this study.

As such, I find it interesting that drivers who are stopped by law enforcement cooperate fully, almost without exception. Often, this cooperation guarantees the driver’s conviction for a crime, particularly the crime of driving under the influence (DUI).

An example of this almost universal cooperation is the field sobriety test. This test is completely voluntary, and the deputies on our island are usually pretty clear about this (although there is no requirement that officers inform drivers that the test is voluntary). Generally, there is little upside legally in taking the field sobriety test. If the driver passes it, it was likely that the deputy did not have enough to arrest the driver for DUI anyway. If the driver doesn’t pass it, the failure will likely be used against the driver in obtaining a conviction for DUI. Yet, drivers at all levels of intoxication almost always agree to the do the test, even in situations where they have already been arrested and are at the Sheriff’s station.

Don’t get me wrong. I have no problem with anyone’s decision to cooperate with law enforcement. In general, I applaud any person who takes personal responsibility for his actions. But, I do not believe the high rate of voluntary submission to this test is a reflection of our society’s desire to take personal responsibility. If anything, it is out of the false hope that cooperation will buy leniency.

All drivers have certain fundamental rights that come into play in a traffic stop situation. While a driver may choose to waive any right voluntarily, I find that most drivers do not know their rights at all. I am going to lay out some of the most important here.

First, law enforcement cannot simply pull a driver over on a whim. An officer has to have reasonable suspicion of a crime or infraction. In a typical traffic stop, the officer observes an infraction being committed, e.g. speeding, expired registration, or a brake light out. But reasonable suspicion of a crime, such as driving with a suspended license or illegal possession of a controlled substance, can form the basis for a traffic stop. Knowing that an officer’s powers to stop and detain a driver are limited is not really helpful in a traffic stop situation. Whether an officer acted properly is something that has to be sorted out later.

Once the officer stops you, he can detain you for the length of time it takes to confirm or dispel his reasonable suspicion. While he can ask a few additional, unrelated questions, most of his energy must be oriented toward the reason for the stop. If, during the stop, he forms reasonable suspicion of an additional crime or infraction, the officer can investigate that as well. Once the officer is through, he must let the driver go unless he has enough evidence to form probable cause of a crime, in which case he can arrest the driver.

When a driver is stopped, he must, upon request, identify himself and present a driver’s license, vehicle registration, and insurance card. The driver should comply with an officer’s reasonable, safety-related requests, such as to move the vehicle to a safer location. The driver’s requirement to cooperate generally ends at this point. If the officer asks the driver to take some act, such as getting out of the vehicle, the driver may ask the officer if he is requiring the driver to do so. You should, under all circumstances, obey an officer’s command. If the command was improper, that can be sorted out later.

While detained, there are certain fundamental rights that a driver has. He has the right to remain silent. Other than identifying himself, he need not speak at all. He can answer all questions, some questions, or no questions. Importantly, if he is later charged with a crime, the jury will not hear that he refused to answer a question. (However, it could hear of a false answer.)

Generally, an officer cannot search the vehicle or the person. There are exceptions too complicated to list here. If an officer asks if he may conduct a search, the driver may ask if his consent to the search is voluntary. If it is, the driver may decline permission. Even if the driver decides to give permission to the officer to conduct a search, the driver may limit the scope of the search (e.g. only the passenger area, not the trunk) and may end the search by withdrawing consent at any time.

As already mentioned, field sobriety tests are always voluntary. Little good can come of this test. If the driver wishes to take responsibility for driving while intoxicated, the driver can simply tell the officer that he is drunk and forego the field sobriety test.

The officer’s decision to arrest the driver changes the character of the encounter. The officer should read the driver his Miranda rights (informing the driver of the right to remain silent and to an attorney) at the point of arrest and certainly before asking any more questions. My advice is always that an arrestee should remain silent and seek an attorney’s advice. If an officer has enough evidence of a crime to arrest a suspect, then it is very unlikely that anything the suspect says will help the suspect’s situation.

If arrested for DUI, there is some post-arrest processing that usually occurs at the Sheriff’s station. Part of this processing is request for a breath test that is more accurate than the PBT. If you wish, the officer must put you in touch with an attorney to help you through this process free of charge. I suggest you always take advantage of this right.

All of this can be difficult to remember when confronted with a suspicious officer. A good point to remember is that a driver can always ask the officer if an answer to his question or an act he is asking for is required or voluntary. A driver should always do what the officer requires him to do. An officer’s violations of a driver’s rights can be sorted out later. If the request is voluntary, and the driver is unsure whether to agree to the request, the better policy is to not do so. Few regret a lack of cooperation with a suspicious officer while any regret too much cooperation.

So, in summary, the question to keep in mind is, “Is that required?”