Withdrawing an Old OUI Plea After the Massachusetts Breathalyzer Scandal: Commonwealth v. Pierre

By Attorney Joe Serpa | Georgetown University Law Center

October 29, 2026

On October 29, 2026, the Massachusetts Appeals Court upheld a judge’s refusal to let Gerald Pierre withdraw the admission he made in a 2015 OUI case in the Dorchester Division of the Boston Municipal Court. Mr. Pierre based his motion on the Massachusetts breathalyzer scandal, the misconduct of the State police Office of Alcohol Testing involving the calibration of Alcotest 9510 breathalyzers. During litigation over those breathalyzers, the Office of Alcohol Testing withheld hundreds of records of failed calibrations from defendants, prosecutors, and judges.

In Commonwealth v. Pierre, No. 25-P-1415, the Appeals Court held that the evidence of intoxication against Mr. Pierre was overwhelming even without the breath test final analysis. Mr. Pierre therefore could not show a reasonable probability that he would have refused to admit to sufficient facts if he had known of the misconduct.

Because the Appeals Court published the opinion, judges in the District Court and the Boston Municipal Court must follow Pierre. In the opinion, the Appeals Court explained how a judge evaluates a motion under Commonwealth v. Hallinan, 491 Mass. 730 (2023), brought by a person whose older OUI case ended with a guilty plea or an admission after an Alcotest 9510 breath test.

The Traffic Stop on Interstate 93 and the 2015 Admission

At about 2:04 A.M. on April 7, 2014, Mr. Pierre drove past a State trooper on an Interstate 93 on-ramp at eighty-five miles per hour. The posted speed limit was fifty-five miles per hour. The trooper stopped Mr. Pierre and walked up to the car. While the trooper stood beside the car, Mr. Pierre lifted his foot from the brake, which made the car jump forward.

The trooper smelled a strong odor of an alcoholic beverage coming from the car and saw that Mr. Pierre’s eyes were bloodshot and glassy. Mr. Pierre’s speech was slurred. After several requests, he stepped out of the car with difficulty. He told the trooper that he was coming from a bar in Boston and had consumed two shots of liquor between 11:30 P.M. and midnight.

The trooper then administered five field sobriety tests. Mr. Pierre did not complete any of the five tests to the trooper’s satisfaction. He recited the alphabet in no particular order after the letter L and could not count backward from eighty-three to sixty-four. On the walk and turn, he repeatedly stepped off the line, stopped walking, and used his arms for balance. He fell backward during the one leg stand, which had to be stopped for his own safety. He also misspelled Massachusetts.

The trooper arrested Mr. Pierre. At the State police barracks, Mr. Pierre urinated heavily and consented to a breath test. During the observation period before the test, he asked for a cup of water, which he drank in less than ten seconds. He fell asleep while waiting to take the test. The breath test final analysis was a blood alcohol content of 0.13 percent. During booking, Mr. Pierre vomited heavily for several minutes. The trooper also noted that Mr. Pierre had a $156 nightclub receipt and the payment card associated with the receipt.

Mr. Pierre was charged with OUI and with the civil infractions of speeding and unsafe operation of a motor vehicle. On September 1, 2015, he admitted to sufficient facts on the OUI charge. By admitting to sufficient facts, a defendant agrees that the Commonwealth’s evidence is enough for a judge to find the defendant guilty. The judge continued the case without a finding for one year and placed Mr. Pierre on probation with conditions that he complete the driver alcohol education program under G.L. c. 90, § 24D and a substance use education program.

Mr. Pierre’s driver’s license was suspended for forty-five days. He was found not responsible for both civil infractions. The court later extended Mr. Pierre’s probation. After he completed the probation, the court dismissed the OUI charge on January 13, 2017.

On August 10, 2023, Mr. Pierre moved to withdraw his admission to sufficient facts. A court treats that request as a motion for a new trial under Mass. R. Crim. P. 30(b). Under that rule, a judge may grant a new trial at any time if it appears that justice may not have been done.

Mr. Pierre supported the motion with his own affidavit, which stated, “If I had known that the breathalyzer results were presumptively unreliable and inadmissible, I believe that I would not have admitted to sufficient facts.” His plea counsel also filed an affidavit, which stated, “Had I known the extent of the issues surrounding the breath test in this matter, I would have explained this to [the defendant], and advised him accordingly as it related to his admission.”

After a hearing, a Boston Municipal Court judge who had not accepted the original admission denied the motion. Mr. Pierre appealed.

The Alcotest 9510 Misconduct and the Hallinan Presumption

The Office of Alcohol Testing, a unit of the State police crime laboratory, certifies the breathalyzers that Massachusetts police departments use. In consolidated District Court litigation known as Commonwealth v. Ananias, OUI defendants challenged the reliability of the Alcotest 9510. The judge in that litigation ordered the Office to produce its annual certification and calibration worksheets for the Alcotest 9510 devices. The Office produced 1,976 worksheets and represented that the production was complete. The Office had intentionally withheld another 432 worksheets that reported failed annual calibrations. Hallinan, 491 Mass. at 733-743.

In Hallinan, the Supreme Judicial Court decided how a person with an older OUI case may rely on that misconduct to withdraw a plea. A defendant who moves to withdraw a guilty plea because of government misconduct must show that egregious government misconduct occurred before the plea. The defendant must also show that the misconduct influenced the decision to plead guilty. Hallinan, 491 Mass. at 744-745.

For the first requirement, the Supreme Judicial Court held that a person whose OUI case included a breath test from an Alcotest 9510 device last calibrated and certified before April 18, 2019, receives a conclusive presumption of egregious government misconduct. The presumption applies whether the case ended with a guilty plea, an admission to sufficient facts, or a conviction after trial. A judge must also exclude the breath test final analysis from any later trial of the case. Hallinan, 491 Mass. at 731.

For the second requirement, a person who pleaded guilty or admitted to sufficient facts must show a reasonable probability that the person would not have pleaded guilty or admitted to sufficient facts if the person had known of the misconduct. The judge decides that question by examining the totality of the circumstances. The Supreme Judicial Court listed five factors for the judge to consider. Hallinan, 491 Mass. at 750.

• Whether evidence of the misconduct could have weakened the facts used to support the guilty plea.
• Whether the evidence could have been used to impeach a witness whose credibility may have been decisive.
• Whether the evidence only repeated other evidence the defendant already had.
• Whether the evidence would have influenced defense counsel’s recommendation about accepting the plea offer.
• Whether the benefits of the plea agreement outweighed the value of the evidence.

In Hallinan itself, the Supreme Judicial Court described the breath test final analysis of 0.23 percent as the “crown jewel,” the most incriminating evidence against the defendant. Ms. Hallinan’s plea counsel stated in an affidavit that he would have advised her to go to trial if he had known that the breath test was inadmissible. The Supreme Judicial Court agreed with the motion judge that Ms. Hallinan had shown the required reasonable probability. Hallinan, 491 Mass. at 750-751.

The Appeals Court’s Reasons for Upholding the Denial

Justice Ditkoff wrote the opinion for a panel of Justices Desmond, Ditkoff, and Toone. The Appeals Court first agreed with Mr. Pierre that an excessive focus on whether the breath test final analysis was the “crown jewel” of the Commonwealth’s case does not help the judge decide the motion.

The Appeals Court had made the same point in Commonwealth v. Crump, 105 Mass. App. Ct. 307, 313 (2025). In Crump, the court wrote that the breath test may have been the crown jewel in Hallinan but that the crown jewel description is not the standard that every defendant must meet.

The Appeals Court then stated the question that the motion judge must answer. The judge asks whether, in light of how the case ended and the evidence other than the breath test, there is a reasonable probability that the defendant would not have admitted to sufficient facts if the defendant had known that the breath test final analysis was inadmissible. The importance of the breath test final analysis to the Commonwealth’s case is one factor the judge considers.

The Appeals Court held that the evidence of intoxication was overwhelming even without the breath test final analysis. Mr. Pierre drove thirty miles per hour over the speed limit on an on-ramp and at first failed to stop his car completely. He had bloodshot, glassy eyes, slurred speech, and an odor of an alcoholic beverage. He had difficulty balancing, counting, spelling, and reciting the alphabet. He admitted drinking two shots of liquor and had a $156 nightclub receipt with him. After the arrest, he urinated heavily, drank water profusely, fell asleep, and then vomited for several minutes.

Given that evidence, the Appeals Court held that Mr. Pierre had not shown a reasonable probability that he would have refused to admit to sufficient facts if he had known that the breath test final analysis was inadmissible.

The Appeals Court contrasted Commonwealth v. Baez, 106 Mass. App. Ct. 219, 221, 224 (2025). Baez concerned the right of a person held on an OUI charge to be examined by a physician of the person’s choosing under G.L. c. 263, § 5A. In deciding that question, the Appeals Court held that the evidence of intoxication in Baez was not overwhelming.

The driver in Baez ran a red light after coming to a complete stop, stepped off the line during the walk and turn, admitted drinking, and had slurred speech and an odor of alcohol. On the booking video, the driver appeared alert, attentive, and compliant with directions.

The Appeals Court described Mr. Pierre’s two affidavits as ambiguous. Plea counsel’s affidavit did not state, even equivocally, that counsel would have advised Mr. Pierre to go to trial. In Hallinan, by contrast, plea counsel stated unequivocally that he would have advised trial. The Appeals Court reasoned that the evidence against Mr. Pierre was so strong that plea counsel could not say he would have given different advice without the breath test final analysis.

Mr. Pierre’s own affidavit stated that he “believe[d]” he would not have admitted to sufficient facts. The Appeals Court noted that the statement was equivocal and held that the judge does not decide the motion on the defendant’s subjective belief. Because a judge cannot evaluate whether a defendant is telling the truth about a decision the defendant never made, the judge evaluates the defendant’s statement under a reasonable person standard. Crump, 105 Mass. App. Ct. at 317.

Given the overwhelming evidence, the Appeals Court held that the motion judge did not err in discrediting what the court called Mr. Pierre’s “self-serving affidavit.” The Appeals Court therefore upheld the order denying Mr. Pierre’s motion to withdraw his admission to sufficient facts.

What the Decision Means for a Person With an Older OUI Case

A person whose OUI case included a breath test from an Alcotest 9510 device last calibrated and certified before April 18, 2019, receives the Hallinan presumption of misconduct without proving the misconduct in that person’s own case. After Pierre, the outcome of a motion to withdraw the plea or admission depends in large part on the evidence other than the breath test final analysis.

In Crump, the Appeals Court listed facts that Massachusetts appellate courts have considered in judging the strength of the Commonwealth’s case without the breath test final analysis. The facts include classic signs of intoxication such as glassy and bloodshot eyes, an odor of alcohol, and slurred speech. The facts also include erratic driving seen by an officer or another witness, a crash, alcohol in the car, an admission to drinking, and the person’s performance on field sobriety tests. Crump, 105 Mass. App. Ct. at 316.

In addition, the judge weighs the affidavits of plea counsel and the defendant. In Crump, the Appeals Court noted that an equivocal affidavit from plea counsel may not shed light on whether a defendant should be permitted to withdraw a plea. Crump, 105 Mass. App. Ct. at 316-317. The judge evaluates the defendant’s own affidavit under the reasonable person standard.

The judge then compares the benefits of the plea with the value of the evidence of misconduct. In Hallinan, the Commonwealth offered no charge concession. The plea judge imposed a two-year loss of Ms. Hallinan’s driver’s license and probation conditions that included weekly Alcoholics Anonymous meetings, a fourteen-day second offender program, and random alcohol testing. The Supreme Judicial Court agreed with the motion judge that the benefits of that plea did not outweigh the value of the evidence. Hallinan, 491 Mass. at 751.

Records of an older case can be lost over time. In Pierre, any record of the exact words of the 2015 plea hearing had been destroyed under the courts’ ordinary record retention rules. The Appeals Court therefore took the facts from the application for the criminal complaint. A person considering a motion under Hallinan should gather the court and docket number, the police report, the breath test documents, the plea paperwork, and the probation, program, and license records as early as possible.

A person convicted of OUI again can face the penalties for a second offense because of an older OUI case that ended with a continuance without a finding. Under G.L. c. 90, § 24(1)(a)(1), the penalties for a second or later OUI apply to a person previously assigned to an alcohol education program because of an earlier OUI, just as the penalties apply to a person previously convicted of OUI. The earlier assignment to the § 24D program remains a prior offense even when the court dismissed the first OUI charge after the person completed probation.

A person facing a second offense OUI charge therefore has a reason to find out whether the first case involved a breath test from an Alcotest 9510 device last calibrated and certified before April 18, 2019.

Attorney Joe Serpa has practiced Massachusetts criminal defense since 1995. Serpa Law Office reviews older OUI cases involving Alcotest 9510 breath tests and represents clients in current OUI cases in the District Court and the Boston Municipal Court.

Frequently Asked Questions About Old OUI Pleas and the Breathalyzer Scandal

Key Takeaways

• In Commonwealth v. Pierre, No. 25-P-1415 (Mass. App. Ct. Oct. 29, 2026), the Appeals Court upheld the denial of a motion to withdraw a 2015 OUI admission to sufficient facts that the defendant challenged because of the Alcotest 9510 calibration misconduct.
• Under Commonwealth v. Hallinan, 491 Mass. 730, 731 (2023), a person whose OUI case included a breath test from an Alcotest 9510 device last calibrated and certified before April 18, 2019, receives a conclusive presumption of egregious government misconduct.
• The person must also show a reasonable probability that the person would not have pleaded guilty or admitted to sufficient facts if the person had known of the misconduct. Hallinan, 491 Mass. at 750.
• A defendant does not have to show that the breath test final analysis was the “crown jewel” of the Commonwealth’s case, but a judge can deny the motion where the other evidence of intoxication was overwhelming.
• A judge evaluates a defendant’s statement about what the defendant would have done under a reasonable person standard. Commonwealth v. Crump, 105 Mass. App. Ct. 307, 317 (2025).

Related Serpa Law Office resources

• Commonwealth v. Hallinan and Massachusetts Alcotest 9510 Cases
• Breathalyzer Defense in Massachusetts
• Breath Test and Blood Alcohol Science in Massachusetts: The Alcotest 9510, the Regulations, and the Blood Rules
• Massachusetts Breath Test and Blood Alcohol Evidence FAQs
• Withdrawing a Guilty Plea After Later-Discovered Police Misconduct
• Second-Offense OUI and the Cahill Disposition in Massachusetts
• Massachusetts OUI and Motor Vehicle Defense