OUI - The Law

  Unlike many other states, an OUI conviction in Massachusetts does NOT require proof the defendant actually drove a vehicle.

The legal definition of “operation” is the intentional manipulation of the ignition or any mechanical part of the vehicle, or use of any electrical agency, which alone or in sequence will set in motion the motive power of the vehicle. This means the vehicle does not need to be in motion or running to sustain a conviction.

Operation can be, and often is, proven with circumstantial evidence.

 The legal definition of a motor vehicle comes from our statutes and the court’s interpretation of the law. To be legally recognized as a motor vehicle the conveyance must be “constructed and designed for propulsion by power other than muscular power, including such vehicles when pulled or towed by another vehicle.” It includes all-terrain vehicles (ATV’s).

Contrary to a common misconception, while cyclists are required to follow “rules of the road,” bicycles, wheelchairs, and mopeds do NOT meet the definition of a motor vehicle in the OUI context.

 For the purpose of an operating under the influence charge, a public way not only includes roads and highways laid out under authority of statute, but also includes places other than roadways depending on the circumstances. For instance, a municipal parking lot allows members of the public a right of access, giving it the same legal effect as a public road in the context of a drunk driving charge. Depending on the circumstances, privately-owned places, such as shopping mall and gas station parking lots may have the same effect as a public way as well.

Evidence may include the manner in which a vehicle was driven (swerving, crossing over the centerline, wide radius turns, and driving too slow) or “visible signs of impairment” (odor of alcoholic beverage on the person’s breath, bloodshot eyes, and slurred speech). 

Other evidence consists of observations made during standardized field sobriety tests [hyperlink] are supported by statistical relevancies. 

Under Melanie’s Law, the OUI statute underwent several changes. The most notable change was creating a per se (automatic) inference that someone with a blood alcohol concentration of .08 or greater is deemed to be under the influence.

The concentration of alcohol in a person's blood is determined by a chemical analysis of a breath sample (Breathalyzer) or a lab analysis of a blood sample.