Breathalyzer results stand at the core of most Massachusetts drunk driving or (DUI) prosecutions and hiring a DUI lawyer who can challenge these readings can be critical. Fortunately, in a trial for DUI in Massachusetts, the alleged drunk driver is legally entitled to have the breathalyzer results excluded if the prosecution fails to meet its burden of demonstrating that the breath testing device used in the case was operating within certain parameters at the time the OUI defendant’s breath was tested. Under this legal standard, in order to introduce breathalyzer evidence in a Massachusetts DUI trial, the prosecution must meet the following 5 requirements.

First, the prosecuting attorney must establish that the officer operating the breathalyzer was properly trained, tested, and certified. Many DUI attorneys overlook this important requirement and they assume that every police officer is properly qualified. This is not the case.

Next, the prosecution must prove that the breathalyzer was approved and certified by the Mass. Office of Alcohol Testing at the time of the breath test. Breathalyzer results from an unapproved or uncertified device are inadmissible. The only two certified evidential breathalzyers which can be used in Massachusetts drunk driving prosecutions are the Draeger Alcotest 7110 and the Draeger Alcotest 9510. 

The prosecution must also show that the breath test was valid. This means that it consisted of 2 sufficient breath samples from the defendant and that the simulator solution was tested and registered .14, .15, or .16. Also, the difference between the two breath samples must be +/- .02 or less.

As a condition of admissibility, the breathalyzer must have been working properly at the time the test was performed and the burden is on the prosecution to establish this. The prosecution must also establish that the defendant consented to the breathalyzer test.

Good Mass. DUI lawyers are able to attack the validity of breathalyzer results and have them excluded from evidence. This can tip the scales well in favor of the defense, even where there is a high alcohol reading. Falsely high breathalyzer readings have been caused by mouth alcohol, diabetes, exposure to solvents, paint thinners and fumes, and even being on the Atkins Diet. Breathalyzers are electronic devices which are no more infallible than any other machine. Breath sample contamination by cold medicines, or mouthwash is possible. 

Also, preliminary or portable breath tests, which are known as PBTs are inadmissible at trial and the only breathalyzers which can produce admissible results are located at police stations and state police barracks. At the point when this breathalyzer test is finally administered, a considerable amount of time may have elapsed since the time when the DUI suspect was actually driving. In light of these factors, DUI lawyers may question whether the chemical breath test administered which was administered so long after the DUI arrest proves anything about the defendant's BAC at the time he or she was driving.