Massachusetts Supreme Court Limits Police Testimony on Marijuana Impairment

The words driving while intoxicated (DWI) or driving under the influence (DUI) are often used synonymously. Usually, when people use either phrase, they default in their minds to drunk driving, and massive amounts of money have been spent on trying to educate people on the dangers of getting behind the wheel after having alcohol.

DWI and DUI are not limited to impairment by alcohol. Drugs and other illegal substances also are included, and driving while under the influence of narcotics like marijuana is as much a crime as driving while drunk.

How the Law Differs

The law is not exactly the same when it comes to driving under the influence of alcohol and drugs, especially in the world of field sobriety tests. These are the roadside tests given to drivers by law enforcement to make an initial determination whether to arrest someone for DUI. They include all the tests that you have probably seen on TV such as walking a straight line, counting backwards, etc., as well as simple observations by officers of a driver’s speech, gait, or mannerisms.

Normally, when it comes to alcohol, an officer can testify whether he or she believed that a driver was drunk or at least impaired, based on the observations made during the roadside test.

The Massachusetts Supreme Court was recently faced with the question of whether officers could give such testimony when the driver was suspected of driving under the influence of drugs, as opposed to alcohol.

How the Science Differs 

Why is this different? Testing has shown us that different people under the influence of drugs like marijuana tend to react differently even with the same amount of the drug in them.

In fact, as was noted by the Court, unlike with alcohol impairment, there is disagreement in the scientific community as to whether the field sobriety test is even an accurate indicator of being impaired. In other words, we know scientifically that with enough alcohol, most people will fail a roadside sobriety test. We do not know this with marijuana, and in fact, some experts believe that excess marijuana, while it may have other effects, would not impair someone’s ability to pass a roadside sobriety test.

Thus, the Court ruled, an officer could not use the results of a roadside test to testify in court that someone was under the influence of marijuana or drugs.

Case Limits but Does Not Eliminate All Testimony

This does not mean that an officer cannot testify at all. Officers can always testify about their observations. For example, they could say they smelled an odor of marijuana, or that the driver’s speech was slurred, etc. The case only prohibits officers from coming to the conclusion that a driver was actually impaired or under the influence of marijuana based on a roadside test, or from saying that a driver “passed” or “failed” the test.

It also may not prohibit an expert in a given field with the proper background from providing this testimony. The case only prohibits police officers from doing so (unless they have some expert training in the proper field). Still, it is a strong case for defendant’s rights, and may help avoid convictions on the basis of testimony that is not based on science or fact.

Make sure you have an attorney who understands what evidence can and can not be used against you. Contact the attorneys of Brassel, Alexander & Rice, LLC today for a free consultation to discuss your case if you are arrested in Maryland.