Massachusetts Breathalyzer FAQs

No. G.L. c. 90, § 24(1)(e) bars refusal evidence in the criminal case, and the Supreme Judicial Court reached the same result under article 12 in Opinion of the Justices, 412 Mass. 1201 (1992). The refusal still triggers a Registry suspension, which is explained on our breathalyzer and license suspension page.

A driver who hesitates and then takes the test produces a result the Commonwealth can use if the regulations were followed, while the hesitation itself stays out of evidence. Once a refusal is recorded, the police are not required to offer the test again, and the Registry suspension follows the refusal. The trial rule stays constant in both directions: valid results come in, and refusals never do.

G.L. c. 90, § 24K and 501 CMR 2.00 require a certified operator, an annually certified device, a 15-minute observation period immediately before the test, and a complete sequence of two adequate breath samples agreeing within 0.02 with a calibration standard analysis reading between 0.074 and 0.086. Missing paperwork or a broken sequence supports a motion to exclude the result.

The device makes two independent measurements: infrared spectroscopy reads the energy ethanol absorbs in the breath sample, an electrochemical fuel cell reads the current the alcohol generates, and the instrument compares the two, flagging the test when they diverge. The Supreme Judicial Court upheld the technology in Commonwealth v. Camblin, 478 Mass. 469 (2017). The science still rests on assumptions, including a fixed breath-to-blood conversion ratio that varies between real people, which is why the compliance rules and records matter in every case.

The regulations require the operator to watch the driver for at least 15 minutes immediately before the test and to restart the period if anything enters the mouth. 501 CMR 2.13(3). The purpose is to keep mouth alcohol, from a burp, reflux, or residue, out of the sample. An observation period that the booking video contradicts is a motion to exclude.

No. The result is admissible only if the device, the operator, and the procedure all satisfied the rules, and the file frequently shows otherwise. Results from Alcotest 9510 devices between June 1, 2011 and April 18, 2019 are presumptively excluded under Commonwealth v. Hallinan, 491 Mass. 730 (2023). Even an admitted number is evidence to be weighed, not a verdict, and the rest of the case still has to survive cross-examination.

The Office of Alcohol Testing withheld hundreds of failed calibration worksheets from defendants, and the courts responded in the Ananias litigation and in Commonwealth v. Hallinan, 491 Mass. 730 (2023). Breath test results from Alcotest 9510 devices between June 1, 2011 and April 18, 2019 are presumptively excluded, and drivers who pleaded guilty in cases with those tests may move to withdraw their pleas.

Yes. Commonwealth v. Camblin, 471 Mass. 639 (2015), entitles a defendant to a reliability hearing on the machine’s methodology, and the Supreme Judicial Court upheld the technology in 2017 only after that scrutiny. The compliance challenges under 501 CMR 2.00 remain available in every case.

The complete file: the device’s annual certification, the calibration and periodic testing records, the operator’s certification, the documentation of the observation period, and the test record showing both breath readings and the calibration standard result. Gaps become motions. Our page on breathalyzer defense explains how each record is used.

There is no single answer, and the tradeoff is concrete. Taking the test can hand the Commonwealth its best exhibit, while refusing produces no trial evidence but triggers a longer, consecutive license suspension with no hardship relief while it runs. The right choice depends on facts no page can know in advance, and the license mechanics are laid out on our license suspension guide.

No. Refusal evidence is barred by statute and by article 12, the prosecutor cannot comment on it, and the jury receives no explanation for the absence of test evidence. The case then turns on driving observations and the roadside exercises, which are covered in our field sobriety test FAQs and taken apart on our page on cross-examination in Massachusetts criminal trials.