OUI / DUI Drunk Driving Defense Lawyer in Greater Boston

A Perfect Jury Trial Record. Thirty Years of OUI Defense Across Eastern Massachusetts.

Attorney Joe Serpa maintains a perfect record of Not Guilty verdicts in OUI jury trials in Massachusetts District Courts and the Boston Municipal Court. That record was built case by case, in courtrooms across Eastern Massachusetts, over thirty years of practice. It is not a marketing claim — it is a factual account of outcomes. See: Massachusetts OUI Trial Results.

An OUI charge under M.G.L. c. 90, § 24 is among the most technically complex criminal matters prosecuted in Massachusetts courts. It involves constitutional law (the legality of the initial stop), administrative law (the RMV’s independent suspension authority), forensic science (the reliability of the Draeger Alcotest 9510 breathalyzer), and clinical medicine (the pharmacology of alcohol absorption and elimination). A defense attorney who does not engage all four of these dimensions is not defending the case. Contact Serpa Law Office at 617.936.0201 for an immediate case review.

What OUI Means in Massachusetts and What the Prosecution Must Prove

OUI — Operating Under the Influence — is Massachusetts’s term for what other states call DUI or DWI. Under M.G.L. c. 90, § 24, the Commonwealth can prove OUI in two ways. The first is impairment — that the defendant operated a motor vehicle while under the influence of alcohol or a controlled substance to a degree that diminished the capacity to operate safely. The second is per se — that the defendant operated with a blood alcohol concentration (BAC) of .08 or above, without requiring proof of actual impaired driving. Both theories can be charged simultaneously. Both are defensible.

The burden of proof is beyond a reasonable doubt — the highest standard in the legal system. A breathalyzer reading is not proof of guilt. An officer’s testimony that the defendant seemed impaired is not proof of guilt. The prosecution must present admissible evidence sufficient to satisfy all jurors unanimously. In thirty years of taking OUI cases to jury trial, Attorney Serpa has not lost one.

The Two Simultaneous Proceedings: Criminal Court and the RMV

An OUI arrest in Massachusetts initiates two entirely separate proceedings that run simultaneously and must be managed simultaneously.

The criminal proceeding in District Court or BMC determines guilt or innocence and imposes criminal penalties — fines, probation, incarceration, and a court-ordered license suspension. A not-guilty verdict or dismissal at this level terminates the criminal case and may restore the license from certain administrative suspensions.

The RMV administrative proceeding under the implied consent law (M.G.L. c. 90, § 24(1)(f)(1)) imposes an automatic license suspension triggered at the time of arrest — independent of any court proceeding. If the breathalyzer was refused: 180 days for a first offense, three years for a second, five years for a third, lifetime for a fourth or subsequent. If taken and registered .08 or above: 30 days for a first offense. These suspensions can be challenged independently of the criminal case. For a complete breakdown see: Massachusetts OUI License Suspensions — A Complete Guide.

Massachusetts OUI Penalties by Offense Number

First Offense OUI (M.G.L. c. 90, § 24)

A first OUI conviction is a misdemeanor carrying up to 2.5 years in a House of Correction and a fine of $500 to $5,000. Most first-time offenders are eligible for the 24D alternative disposition under M.G.L. c. 90, § 24D — a probationary resolution involving a 45-to-90-day license loss and completion of an alcohol education program, available once in a lifetime. The 24D is not a conviction under Massachusetts law but is treated as a prior offense for any future OUI charge and carries significant collateral consequences for licensed professionals, CDL holders, non-citizens, and federal employees.

Second Offense OUI

A second OUI conviction carries a mandatory minimum of 60 days in a House of Correction (30 days to serve), a two-year license revocation, and a fine of $600 to $10,000. Second offenders must complete a 14-day inpatient alcohol treatment program. An ignition interlock device (IID) is mandatory on any reinstated or hardship license. The Cahill disposition under Commonwealth v. Cahill permits a second offense to be treated as a first for sentencing when the prior offense is more than ten years old.

Third Offense and Felony OUI

A third OUI conviction is a felony carrying a mandatory minimum of 150 days in a House of Correction, an eight-year license revocation, and a fine of $1,000 to $15,000. A fourth OUI carries mandatory state prison exposure of up to five years and a 10-year license revocation. A fifth or subsequent OUI carries up to five years in state prison and permanent lifetime license revocation. Prior OUI convictions from any state count toward the Massachusetts prior-offense calculation. There is no look-back period — a conviction from thirty years ago is a prior.

OUI Causing Serious Bodily Injury (M.G.L. c. 90, § 24L)

A felony carrying a mandatory minimum of six months in a House of Correction and up to 2.5 years in a House of Correction or up to 10 years in state prison, with a two-year license revocation. These cases involve accident reconstruction experts and forensic toxicologists and require the most experienced trial defense available.

OUI Manslaughter (M.G.L. c. 265, § 13½; M.G.L. c. 90, § 24G)

A mandatory minimum of one year in prison and up to 15 years in state prison, with a 15-year license revocation. Among the most serious charges in Massachusetts criminal law — requiring immediate retention of experienced trial counsel.

The Defense: How Massachusetts OUI Cases Are Won

Layer 1: The Constitutionality of the Stop

Before any other evidence matters, the traffic stop must have been constitutionally lawful. Under the Fourth Amendment and Article 14 of the Massachusetts Declaration of Rights, an officer must have reasonable articulable suspicion of a motor vehicle violation or criminal activity before initiating a stop. A stop based on a hunch, an anonymous tip without corroboration, or a violation that did not actually occur is unconstitutional. Evidence obtained from an unconstitutional stop — including officer observations, field sobriety tests, and breathalyzer results — is suppressible in its entirety through a Motion to Suppress. When the suppressed evidence is the totality of the Commonwealth’s case, dismissal follows.

Layer 2: The Field Sobriety Tests

The three Standardized Field Sobriety Tests (SFSTs) — Horizontal Gaze Nystagmus (HGN), Walk and Turn (WAT), and One Leg Stand (OLS) — are voluntary in Massachusetts and carry no license suspension penalty if refused. When administered, they must be conducted in strict compliance with NHTSA guidelines: proper lighting, level surface, pre-test instructions given verbatim, clues scored precisely. Any deviation from protocol is grounds for a motion to exclude the test results or aggressive cross-examination of the administering officer. Body camera and dash camera footage routinely contradict officer field sobriety scoring and are demanded in every case.

Layer 3: The Breathalyzer

The Draeger Alcotest 9510 is the only breathalyzer approved for evidentiary use in Massachusetts under 501 CMR 2.00. Attorney Serpa reviews the following in every OUI case:

• The 15-minute continuous observation period required before administration — any break is grounds for a Motion to Suppress the entire result
• Calibration and maintenance records for the specific Draeger machine used in the arrest — following Commonwealth v. Ananias, which resulted in exclusion of over 27,000 breath tests statewide, these records must be demanded and audited in every case
• The .02% internal consistency requirement — if the two required breath samples vary by more than .02% BAC, the result is invalid under 501 CMR 2.00
• The defendant’s specific medical conditions — GERD, acid reflux, diabetes, and certain medications can artificially inflate a breathalyzer reading through mouth alcohol contamination
• The rising BAC phenomenon — alcohol continues to absorb after consumption, meaning a person can be below .08 while driving and above .08 at the time of testing

See our full analysis: Why a Failed Breathalyzer Does Not Equal an OUI Conviction in Massachusetts.

Layer 4: The Trial

When motions are denied and the case proceeds to trial, the defense continues. A jury deciding an OUI case must reconcile the breathalyzer number against the human being they see in the courtroom and in the booking room video. Attorney Serpa has tried OUI cases in which the defendant had a BAC of .11, .13, and higher — and won not-guilty verdicts at all of them. The trial strategy presents the complete picture: booking video showing the defendant speaking clearly and walking without difficulty; dash camera footage showing controlled, lawful driving; witness testimony from persons present at the time; and expert testimony challenging the reliability of the specific machine result.

See: Fighting an OUI in Massachusetts: How Cases Are Won at Trial and Massachusetts OUI Trial Results.

OUI Defense for Specific Populations

Licensed Professionals

For physicians, attorneys, nurses, financial advisors, engineers, and other licensed professionals, an OUI charge carries consequences beyond the criminal case. The Board of Registration in Medicine, the Board of Bar Overseers, the Division of Professional Licensure, and FINRA all treat an OUI conviction — and in many cases a CWOF — as a reportable disciplinary event. Healthcare professionals with DEA prescribing authority face additional federal consequences. The defense strategy for licensed professionals prioritizes a trial outcome or pre-trial dismissal rather than a CWOF, because the CWOF’s collateral licensing consequences are often identical to those of a conviction.

College and University Students

For university students in the Boston and Cambridge area, an OUI conviction or CWOF under the Junior Operator Law (M.G.L. c. 90, § 24P) carries a 210-day license suspension, a CORI entry, and a potential university disciplinary proceeding. The defense of student OUI cases focuses on suppression of breathalyzer and field sobriety evidence, motion practice, and — where a clerk-magistrate hearing is available — pre-arraignment resolution that prevents any CORI entry.

CDL Holders and Commercial Drivers

CDL holders face a federal BAC threshold of .04 under 49 C.F.R. § 382.201 and mandatory CDL disqualification of one year for a first OUI conviction — regardless of whether the vehicle driven was a commercial vehicle. A second OUI results in lifetime CDL disqualification. A CWOF is treated as a conviction for CDL purposes under federal regulations. For commercial drivers, the defense of an OUI case is career-defining, and the standard for accepting any resolution short of dismissal or not guilty is correspondingly high.

Non-Citizens and Visa Holders

A first-offense OUI conviction does not categorically qualify as a crime of moral turpitude or an aggravated felony under federal immigration law. However, an OUI involving drug impairment can constitute a controlled substance offense with permanent immigration consequences. A second OUI can become an aggravated felony if it involves significant incarceration. A CWOF is treated as a conviction for federal immigration purposes under 8 U.S.C. § 1101(a)(48)(A). Any non-citizen facing an OUI charge should have the immigration consequences assessed by an attorney before accepting any disposition. See: Immigration Consequences of Massachusetts Criminal Charges.

Courts Where Serpa Law Office Handles OUI Cases

OUI cases under M.G.L. c. 90, § 24 are prosecuted in the District Court or Boston Municipal Court with jurisdiction over the location of the traffic stop. Each courthouse has its own judges, prosecutors, and local procedural culture. Attorney Serpa has tried OUI cases in each of these courts over thirty years:

Hingham District Court, Plymouth County DA. Route 3 South, Route 3A, and the South Shore Expressway. Hingham, Norwell, Scituate, and Cohasset stops.Contact Serpa Law Office at 617.936.0201 for a free consultation. Boston office: 20 Park Plaza #400A. Quincy office: 500 Victory Rd., Suite 400A. Available 24 hours a day.

Boston Municipal Court (BMC), Suffolk County DA. Central, Brighton (Route 9 and Comm. Ave. stops), East Boston (Route 1A and airport approaches), South Boston (I-93 and Route 3A), Roxbury, Charlestown, Dorchester, and West Roxbury divisions.

Quincy District Court, Norfolk County DA. Route 3, Route 3A, Route 128 (I-93) South, and the Southeast Expressway corridor. Serpa Law Office Quincy office is minutes from the courthouse.

Dedham District Court, Norfolk County DA. I-95, Route 1, and Route 128 stops in Dedham, Norwood, Westwood, Needham, and Wellesley.

Brookline District Court, Norfolk County DA. Route 9 and Brookline Avenue stops.

Newton District Court, Norfolk County DA. Route 128, Route 9, and the Mass Pike (I-90) Newton exits.

Cambridge District Court, Middlesex County DA. Memorial Drive, Route 2, and Fresh Pond area stops. A court with significant experience in breathalyzer challenge litigation.

Somerville District Court, Middlesex County DA. Route 28, McGrath Highway, and I-93 Somerville exits.

Woburn District Court, Middlesex County DA. I-93 North, Route 128 (I-95) North, and Route 3 North through Burlington, Woburn, and Wilmington. High volume of OUI cases from the I-93/Route 128 interchange.

Waltham District Court, Middlesex County DA. Route 128 (I-95) Waltham exits and the Route 20 corridor.

Malden District Court, Middlesex County DA. I-93 Malden and Revere stops. Route 1 North corridor.

Framingham District Court, Middlesex County DA. Mass Pike (I-90) through Framingham and Natick. Route 9 and Route 30 MetroWest corridor.

Concord District Court, Middlesex County DA. Route 2 and Route 2A through Lincoln, Concord, Acton, and Maynard.

Call or Contact Serpa Law Office today for a free consultation.