Understanding OUI Arrests and Breath Tests in Massachusetts


Scroll Down to See Cases We've Won Despite Failed Breathalyzer

When you have been pulled over and are suspected of drunk driving, you could be asked to provide a breath sample. Misconceptions exist about what your rights are and what these types of tests are. Misunderstandings can lead to more problems, especially if you are facing OUI charges in Massachusetts

Attorney Dunn helps clients understand all aspects of their Massachusetts drunk driving case. We believe informed clients make better decisions about how to proceed. If you have questions or want to speak to an OUI lawyer in Massachusetts, call us now at 617-504-4881 to get your free consultation.

What Are Breath Tests?

Police officers use breath tests in roadside testing and following arrests to help determine whether an alleged drunk driver was under the influence of alcohol while operating a vehicle. These tests can be used for operators of cars and trucks as well as operators of motorcycles, boats, and other vehicles as defined by their respective state.

There are two different types of breath tests: the portable, preliminary breath test (PBT) (also known as preliminary alcohol screenings) and the breathalyzer. Both "types" are often simply called "breath tests," and that's where the confusion comes in. By referring to both as breath tests, people assume they are the same thing, but they are not. Each is administered for different reasons and purposes.

Preliminary Breath Tests

A preliminary breath test or alcohol screening is a breath alcohol test conducted using a portable breath machine in the field, meaning on the side of the road during a traffic stop or OUI investigation. The PBT presumes to measure a person's breath alcohol content (BrAC). Portable breath test results are almost always inadmissible in court because they are unreliable. You would want to speak to a drunk driving attorney, however, regarding PBT results and admissibility specifically in your case.

PBTs are administered when a police officer has reasonable grounds to believe you are unlawfully driving under the influence. Maybe your speech was slurred or your eyes were bloodshot, and so the officer asks to take a breath sample. If you fail the PBT, that could be enough probable cause to arrest you for a drunk driving offense. A PBT result can also be used in conjunction with a failed field sobriety test as sufficient probable cause to arrest you.


After an arrest for a drunk driving offense, you will be asked to take another test. Typically, this is a chemical test using a breathalyzer. The breathalyzer is not a portable machine and produces results that are more accurate and can be admitted into court as evidence against you. Massachusetts uses only one type of breathalyzer, the Dräger Alcotest 9510 machines that are subject to calibration requirements established by state law.

Before you provide a breath sample via a breathalyzer, the officer should have read the Statutory Rights and Consent form to you. That form should advise you of your rights before officers ask for your consent to submit to a breath test. If this warning was not provided to you prior to a breathalyzer test, your rights may have been violated.

Common Problems with the Breath Tests in Massachusetts

Breath tests using portable machines are known to be unreliable, and that's why they are typically not admissible in court. Breath tests using breathalyzers at the police station, however, are admissible. They, too, can also be unreliable and become inadmissible under certain situations or circumstances.

Problems with breathalyzers can be categorized as those resulting from the testing device or machine, the individual operating the device or the test sample.

Problems with the Breathalyzer Device

  • Improper calibration
  • Incorrect chemical solutions
  • Inappropriate modification
  • Faulty programming
  • Broken or otherwise not maintained properly

Issues with the Administration of the Test

  • Failure to read Statutory Rights
  • Improper instructions or methodology
  • Failure to follow testing protocols
  • Testing performed by an untrained person

Causes of Improper Breathalyzer Test Readings

  • Pre-existing conditions or other medical conditions suffered by the test taker
  • Medications, foods, or drinks
  • Residual alcohol from the test taker's mouth

Breath tests can be challenged. We can file motions to suppress or exclude the results. Sometimes, if successful, this could result in dismissal of the charges or an acquittal.

Five Ways We Challenge OUI Breath Tests in Massachusetts

A breath test is often a substantial part of the prosecution's case involving OUI offenses. For that reason, it is essential to ensure that a breath test was performed correctly and the results are accurate. We have been well trained and have experience in these cases can identify a problem with a breath test and take proper action to suppress it as evidence.

We can take any of the following actions, depending on the specific facts and circumstances of your case:

  1. Attack the reliability of the breath test. Many reasons exist why we may not be able to rely on the results of a breath test, like a faulty machine, improper administration, or health issues with the test taker.
  2. Prove the breath device was not properly calibrated. Each state has its respective laws on calibration, but it usually involves a certified forensic analyst and verification of the machine's accuracy.
  3. Prove device was not properly maintained. Typically, the date and time of repairs and maintenance, as well as the nature and extent of and who performed the maintenance and repairs must be logged.
  4. Prove there was a lack of training or an operator's error. Police must be trained in order to conduct breath tests. An untrained or uncertified police officer may not properly administer the test.
  5. Prove records were not properly maintained. Records should be kept to show proper calibration and maintenance, and failure to keep those records updated can be used to prove the device was not properly calibrated or maintained as the law requires.

During the discovery phase of your case, we will obtain the information and evidence we need to support arguments against the breath test's admissibility.

Contact Massachusetts OUI Defense Attorney James Dunn Now

You can have your day in court to challenge OUI charges regardless if you took and failed a breath test or refused one. With the right OUI defense lawyer in Massachusetts, you can be successful. Contact OUI defense attorney James Dunn today by calling us at 617-504-4881 or filling out an online form to get your free consultation.

Cases We've Won Despite Failed Breathalyzer

Cole, Somerville
Accident, Failed Breath Test
Not Guilty 1st Offense
I can't thank attorney James Dunn enough. He always listened and understood things from my perspective. He always responded quickly and answered all my questions. And he always gave me the best advice. James told me to fight the case from the beginning, even though there was an accident and a failed breath test. At trial, he kept the breath test out and won a NOT GUILTY!
I couldn't be happier with what he did for me.

Docket 20220928
Click Here to See Cole's Court Docket

Deborah, Framingham / Natick
1st Offense, Lanes Violation
Failed Breath Test
Charges Dismissed!
Cop saw Deborah cross marked lanes and pulled her over. He noted she was unsteady on her feet and her speech was slurred. After performing a field sobriety test, he decided to arrest her. At the station, she registered a .12 on the breath test, well above the legal limit of .08. During the nearly two years in which Aty. Dunn represented her, he successfully excluded the breath test from evidence rendering it a triable case. When the officer failed to show up for court, he argued vociferously for dismissal of all charges. The judge agreed.

Sarah, Westboro / Worcester
2nd Offense, .19 Breath Test
Not Guilty After Jury Trial
Police report indicated Sarah was unsteady on her feet, had a strong odor of alcohol, and  failed the one leg stand and walk and turn test.  At the station, she took the breathalyzer and blew a .19, almost two and one half times the legal limit.  In the almost two years it took to reach trial, Attorney Dunn negotiated the exclusion of the breath test and then convinced the jury there was reasonable doubt.  Not guilty of OUI 2nd offense and not guilty of reckless driving.
From Sarah: "I'm so relieved!"
"I can finally move forward & do all the things I want in life"

See Sarah's Google Review Here

Tony, Wrentham
Failed Breath Test
OUI 2nd Offense - Not Guilty
Negligent Operation - Not Guilty
Police report stated Tony was speeding, drove on opposite side of road briefly, had glassy, bloodshot eyes, slurred speech, an odor of alcohol and admitted drinking. Then he failed both the roadside field test and then the breath test at the station. Attorney Dunn had the breath test thrown out and then won a not guilty on both charges after trial.
"Attorney Dunn told me to fight and helped me make all the right choices."

AJ, Woburn
Accident & Failed Breath Test
Not Guilty at Trial
After AJ rear ended another car, Trooper gave him three field sobriety tests and then arrested him. At the state police barracks, he agreed to take a breathalyzer test but failed it and lost his license. However, we ultimately managed to have the failed breath test result excluded from the evidence against him. At trial, attorney Dunn then convinced the judge to find him not guilty.
"Best Legal Advice Ever!"
"Saved My License and Saved My Job"

Terry, Fitchburg
5th Offense
Failed Breath Test
Jury: "Not Guilty" in 5 minutes
Terry faced a mandatory 2.5 year jail sentence if convicted plus a lifetime loss of license. He was stopped for speeding. Officer noted a strong odor of alcohol and that his speech was slow and slurred. He stumbled getting out of the car and did not perform well on the 9 step walk and turn test. On the one leg stand, he was unable to keep his foot up more than a couple of seconds despite multiple tries. At the station, he took the breathalyzer and failed. After keeping the breath test out of evidence, we went to trial. We stressed to the jury he pulled over promptly and safely, did the tests in heavy hiking boots in the cold at 1:45 AM and recited the alphabet correctly. He was found not guilty and attorney Dunn convinced the judge to order the RMV to immediately restore his license.
No Lifetime License Loss
Per Terry: "It made a huge difference having a real lawyer at my side"

Jeffrey - Salem
Accident, .19 Breath Test
Not Guilty 2nd Offense After Jury Trial
Jeffrey rear ended a large truck and tried to drive away but was unable to get very far. His breath test was 2 1/2 times the legal limit. We immediately filed a Motion to Preserve the Booking Video which showed him speaking and walking perfectly normally. After the breath test was thrown out, he chose trial where both the police and a civilian witness testified against him. However, attorney Dunn convinced the jury to find him not guilty.
"Represented me for 26 months and never asked for more money!"

Docket 20211026
Click Here to See Jeffrey's Court Docket

K.D., Belchertown
I was only 20 years old when arrested for OUI and failed the breath test at the station. That caused a 180 day license loss but attorney Dunn showed me how to avoid that. Then, on the day of his Motion to suppress the breath test, he convinced the DA to drop the OUI completely. I will not suffer license loss of almost 1.5 years and will end up with no criminal record.
"I ended up with no criminal record"

Donald, Boston / Charlestown
Failed Breath Test & Roadside Tests
2nd Offense - All 6 Charges Dismissed
Attorney Dunn went beyond my wildest expectations. He was always with me in court, always on time and always prepared. He never gave up fighting for me for almost two years. I didn't think I had a chance because I failed the field tests and the breath test. But, incredibly, James got the breath test thrown out of court! Then he was able to convince the judge to dismiss all 6 charges. That saved me from a two year license loss, a possible jail sentence, and thousands of dollars in fines and fees.
"James Dunn saved my job!"

Joey, Clinton / Fitchburg
Breath Test .26 - Over 3 Times Limit
Not Guilty of OUI After Jury Trial
I thought I was dead to rights. I blew a. 26 on the breath test which was 3 times the legal limit. Somehow, James got the DA to agree to keep it out of evidence against me at trial. Plus, the civilian caller who followed me  also showed up at trial and took the stand but James pointed out inconsistencies in his testimony. There was even a bad video but James totally turned that around on them.
"James is totally together. He had the DA scrambling. I give him 5 stars."
"He's a rock star!"

Christine, Lawrence
Case Dismissed
Despite Accident & Failed Breath Test
We hired you for my daughter because you were genuinely interested and compassionate. Your answers to all our questions were detailed yet simple to understand. You kept everything on a positive note giving us comfort that we were represented by a knowledgable and professional law firm. Despite her accident and failed breath test, attorney Dunn achieved a dismissal of all the charges against her. Kudos for your efforts, compassion and a job well "Dunn."  -Frank C. (father of Christine).
"Attorney Dunn Won Me a Dismissal of All Charges"

Bert, Natick / Framingham
Failed Breath Test - Not Guilty!
Cop saw Bert cross marked lines 5 times and wrote he had bloodshot eyes, slurred speech and a strong odor of alcohol. Bert also told the officer he had his last drink 1 hour before the stop and was arrested after doing field sobriety tests.  At the barracks he took the breathalyzer test and failed it. At trial, attorney Dunn argued he was able to produce both documents without issue showing nothing wrong with his fine motor skills and he exited the car perfectly normally and walked perfectly normally creating the necessary reasonable doubt. Judge found him not guilty.  He was also found not responsible of the other two charges.
"Attorney Dunn is an experienced, professional OUI expert!"

Steve, Woburn
Failed Breath Test
Speeding 20 MPH Over the Limit
Not Guilty - 1st Offense
'James Dunn is a great lawyer. He was diligent and communicative throughout the whole process. He always advised me to take my time and think through all the options and outcomes. He worked hard to win my case and made me feel like I was his only client. I wholeheartedly endorse him. A great and patient lawyer that will work hard to get you the outcome you hope for.'
"Attorney James Dunn made me feel like I was his only client"

Chris, Springfield
Failed Breath Test .12
Failed Field Tests
Not Guilty - 1st Offense
"Attorney Dunn was thoroughly professional from start to finish. I was worried about how it would turn out but he put me at ease. He did a great job at jury trial and dramatically caught the trooper in not just one but two lies. The jury didn't like that at all!  They found me not guilty of OUI and not guilty of reckless driving. I couldn't recommend him more highly."
"Attorney Dunn kept me at ease throughout."
"I couldn't ask for a better result."

James, Concord/Newton
3rd Offense
Failed Breath Test .17
James Dunn had to go back to the other court three times before the clerk finally found the recored of my first OUI in the basement. That made all the difference at trial. The DA wanted to give me a two year jail sentence but James's firm talked the judge out of it and proved the first OUI shouldn't count against me. I can't believe how hard they worked for me. They're fantastic.
Mandatory Jail & Felony Conviction Avoided

Attorney Dunn Is Here for You

Attorney James Dunn is an OUI / DUI lawyer who proudly and vigorously defends clients in OUI matters across Massachusetts

Contact Attorney Dunn Today

Here for you when you need me 24/7. Call now, no matter what time it is. I will respond immediately: 617-504-4881.

Reviews & Recommendations

See the growing list of reviews and recommendations. Call me now to discuss how I can help you - I promise to act in your best interest at all times: 617-504-4881.