• Michael Thaler, Esq

How much do field sobriety tests matter in a DUI/OUI case?

In a DUI/OUI case in Massachusetts, the most common features are field sobriety tests and breathalyzers. In nearly every case, a police officer or state trooper will ask someone that he or she is investigating for a DUI/OUI to perform field sobriety tests prior to deciding whether to arrest that person for a DUI/OUI. Therefore, an important question to ask is how much do field sobriety tests matter in a DUI/OUI case?


Field sobriety tests are incredibly important in a DUI/OUI case in Massachusetts. They are often the main piece of evidence used by both the prosecutor and the defense attorney at a DUI/OUI trial to argue that the defendant is either guilty or not guilty. Field sobriety tests are often referred to as divided attention tests as they are meant to see how a person who is suspected of being under the influence of either alcohol or drugs is able to perform on a task that requires the person to do multiple things at the same time. There are several field sobriety tests that are commonly utilized in all DUI/OUI cases:


  1. Horizontal gaze nystagmus test (aka “HGN test”): a test in which a police officer or state trooper looks at a person’s pupils while the person is asked to track the police officer or state trooper’s finger as he or she moves the finger laterally in front of the person. This is a field sobriety test of the eyes. In general, the HGN test is inadmissible in a DUI/OUI alcohol trial and can sometimes be used in a DUI/OUI drug trial so long as there is a properly trained police officer/state trooper.

  2. Walk and turn test: a test in which a person is asked to walk in a straight line for nine steps while touching heel-to-toe, keeping his or her arms by his or her side, and counting out loud each step before doing a specific pivot and then nine steps back in the same fashion.

  3. One leg stand test: a test in which the person is asked to stand on either leg of his or her own choosing, lift the foot approximately six inches off the ground, point the foot forward, and count to either thirty or until told to stop while keeping his or her arms by his or her side.

  4. Portable breath test (aka “PBT”): a hand-held breathalyzer that is done road-side by a police officer or state trooper. The PBT is always inadmissible in DUI/OUI trials because it is not considered scientifically reliable, but it is utilized by police officers and state troopers as part of the probable cause analysis to arrest.


Some other field sobriety tests that are utilized by officers in addition to the above four include the following:


  1. Alphabet test: a test in which a person is asked to recite the alphabet, either in its entirety or a portion of it, without singing it.

  2. Count backwards test: a test in which a person is asked to count backwards from one specified number to a second specified number.

  3. Modified Romberg test: a test in which a person is asked to estimate the passage of thirty seconds while standing with his or her feet together, head titled slightly back, and with his or her eyes closed. This test is generally only used in a DUI/OUI Drugs case.


Knowing what each field sobriety test entails, it is easy to see why they are so important to a DUI/OUI case. If a person is able to perform the field sobriety tests close to as instructed, then it can be utilized by an experienced Massachusetts DUI/OUI lawyer to argue that there is reasonable doubt. If a person has significant trouble performing the field sobriety tests, then it becomes a more difficult case for a Massachusetts DUI/OUI lawyer to successfully defend at a trial. However, there are many issues that can still be argued by an experienced Massachusetts DUI/OUI lawyer in the Boston and Dedham areas to minimize the importance of the field sobriety tests. For instance, the field sobriety tests are less “reliable” when the person involved is elderly, overweight, or suffers from medical issues that affect balance or coordination.


Recent case law has also clarified that field sobriety tests should be given even less weight in Massachusetts DUI/OUI Drug cases. In Commonwealth v. Gerhardt, 477 Mass. 775 (2017), the Supreme Judicial Court of Massachusetts indicated that “there is as yet no scientific agreement on whether, and, if so, to what extent, these types of tests are indicative of marijuana intoxication.” As such, the Court made the following findings that are very advantageous for an experienced Massachusetts DUI/OUI lawyer to utilize in a DUI/OUI Drug case, especially when the alleged drug is marijuana:


  1. Field sobriety tests should be referred to as “roadside assessments”.

  2. The police officer or state trooper cannot make any statement as to whether the driver's performance would have been deemed a “pass” or a “fail” or whether the performance indicated impairment.

  3. Neither a police officer nor a lay witness (non-expert) may offer an opinion as to whether a driver was under the influence of marijuana.


The Gerhardt decision showcases how field sobriety tests, which are relied on so heavily by the Commonwealth, have much less impact on a DUI/OUI Drugs case. To learn more about DUI/OUI marijuana cases, CLICK HERE.


Given how important field sobriety tests are in a Massachusetts DUI/OUI case, the next question is whether a person is required to take field sobriety tests. The answer is no, a person is allowed to refuse to take field sobriety tests. In fact, if a person refuses to perform field sobriety tests, it cannot be brought up at trial in any capacity. Pursuant to Commonwealth v. McGrail, 419 Mass. 774, 647 N.E.2d 712 (1995), evidence of a defendant's refusal to submit to field sobriety tests constitutes testimonial or communicative evidence, thus it cannot be admitted since its use violates the defendant's privilege against self-incrimination. This is the same rationale for why a refusal to take a breathalyzer is inadmissible at a trial. There are several important distinctions between a field sobriety test vs breathalyzer. If a person is arrested but does not go to the hospital, the police officer or state trooper is required to offer the person under arrest the opportunity to do a breathalyzer. Field sobriety tests generally occur prior to arrest, not afterwards. Also, a refusal to take a breathalyzer at the police station/barracks (not the PBT, which is considered a field sobriety test) will result in an automatic license suspension of at least six months, but a refusal to do field sobriety tests has no similar collateral consequences.


Finally, the question is whether a person should refuse to take field sobriety tests. If you do not take field sobriety tests, then it is likely you will be arrested based on the information that the police officer has at the time that led him or her to ask you to do the tests. In very rare situations, performing the field sobriety tests exceedingly well or having a PBT result of under 0.06 may result in a police officer or state trooper releasing the person rather than placing him or her under arrest. But it is very unlikely that a person will know how he or she will do on the field sobriety tests prior to actually performing them. The benefit in the long run of refusing to take field sobriety tests is that the Commonwealth will have far less evidence that they can use at a trial, leading to a better chance at being found not guilty.


If you have been charged with a DUI/OUI in Massachusetts, it is important that you speak to an experienced DUI/OUI lawyer who is familiar with all the intricacies of field sobriety tests so that you have the best possible chance at being found not guilty at trial. Attorney Michael Thaler handles DUI/OUI cases throughout Massachusetts, especially in the Boston, Dedham, Attleboro, Wrentham, Quincy, Stoughton, Brookline, Brighton, Orleans, Barnstable, Waltham, Somerville, Brockton, and Taunton areas. Contact Attorney Michael to schedule a free consultation at 781-366-0806 or mike@thaler.law.


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