Preliminary breathalyzer test result, PBT, are inadmissible to prove a DUI offense in Massachusetts. Accordingly, if you failed a portable breathalyzer test the Commonwealth cannot offer that evidence to the jury.

A case from Wisconsin raised an interesting issue of whether a defendant can offer preliminary breathalyzer test results to show that the defendant’s blood alcohol level was lower at the time of driving. The DUI lawyer in this case retained an expert who used the results of the preliminary breathalyzer test to argue to the jury that the defendant was still in the absorption phase and his blood alcohol level was lower at the time of driving than at the time the breathalyzer test was given.

The answer to this question would seem to be yes, how can the state disclaim the scientific reliability of its own evidence and deprive the defendant of his right to present a defense and exculpatory evidence. The Wisconsin Supreme Court rejected this argument, relying on the intent of the legislature to limit the admissibility of portable breathalyzer test results.

The court’s ruling reconciles two Wisconsin Statutes – Wis. Stat. sec. 343.303 and Wis.Stat.sec. 907.03. Wis. Stat. sec. 343.303 expressly prohibits the use of a PBT to prosecute a motorist accused of operating a motor vehicle while intoxicated. On the other hand, Wis.Stat.sec 907.03. provides for the admissibility of expert opinion testimony regardless of the admissibility of the underlying data. The defendant contended that even though the portable breathalyzer is inadmissible that his expert’s opinion should be allowed because the expert relied upon it in reaching his opinion. The defendant attempted to draw a distinction between offering the PBT results. which he was not doing and offering testimony that relied on the PBT results. The court held that is no distinction and the statute prohibiting PBT results from being admitted into evidence would be violated by allowing the expert to rely on them in forming his opinion.

The Court held that the legislative policy was clear that portable breathalyzer test results are inadmissible. The court reasoned the legislative intent behind limiting the admissibility of PBT results “helps law enforcement officers do their jobs with more cooperation from drivers than they would otherwise be likely to get if the results were admissible in court. The court noted that a PBT may be requested when an officer has a basis to justify an investigative stop but has not established probable cause to justify an arrest.

Similarly under Massachusetts law, preliminary breathalyzer tests are inadmissible. PBT have never been deemed scientifically reliable and as a result, may not be used as evidence against a defendant.

The Massachusetts courts have not addressed whether a defendant can offer the PBT. If this occurred in Massachusetts, the court probably would allow a defendant to offer the results of the PBT as the decision of the Wisconsin Supreme Court appears to deny the defendant his right to present a defense and cross examine the State’s evidence under the Sixth Amendment and Fourteenth Amendment to the United States Constitution.

If you are facing Massachusetts OUI charges or if you’ve failed a breathalyzer test it’s crucial you contact an experienced Massachusetts OUI/DUI attorney who understands the proper procedures the Commonwealth must follow before administering a breathalyzer test and the grounds for excluding breathalyzer results.

If you are charged with a Massachusetts DUI, call Attorney DelSignore for a free consultation, 24 hours a day, including weekends and holidays. Attorney DelSignore will schedule an immediate appointment to discuss your case and answers most calls personally. You can also send an email through this site which will be replied to immediately.