1:7. Under the influence of alcohol

Research References

West's Key Number Digest, Automobiles &key;332

C.J.S., Motor Vehicles §§1382 to 1394

There are two ways that the Commonwealth may prove that a motorist is “under the influence.” The first way is to prove that the person ingested enough alcohol to diminish their ability to operate a motor vehicle safely. If the Commonwealth chooses to proceed under this theory alone, and chooses to offer evidence of a breath or blood alcohol level, it must offer evidence that would relate such a level back to the time of driving, and the connection between the alcohol level and the driving impairment. The second is by proving that the person had a blood alcohol level of .08% or greater.

1:8. Diminished capacity

Research References

West's Key Number Digest, Automobiles &key;332

West's Key Number Digest, Automobiles &key;355(6)

C.J.S., Motor Vehicles §§1382 to 1394

C.J.S., Motor Vehicles §§1408 to 1411

C.J.S., Motor Vehicles §1545

The current standard the prosecution must achieve was set forth in Commonwealth v. Connolly.

In Connolly, the Supreme Judicial Court stated “in a prosecution for operating a motor vehicle while under the influence of intoxicating liquor, the Commonwealth must prove beyond a reasonable doubt that the defendant's consumption of alcohol diminished the defendant's ability to operate a motor vehicle safely. The Commonwealth need not prove that the defendant actually drove in an unsafe or erratic manner, but it must prove a diminished capacity to operate safely.” However, another fair interpretation of the statute would prohibit driving only if alcohol has affected the driver to such a degree that the driver threatens the public welfare. Proof of drunkenness is not required to establish impairment. A motorist can be found to be operating under the influence of intoxicating liquor “‘if the liquor that he has taken influenced his driving to any perceptible degree.'”However, the Commonwealth must prove beyond a reasonable doubt that defendant's consumption of alcohol diminished the defendant's ability to operate a motor vehicle safely. The Commonwealth need not prove that the defendant's drinking rendered his actual operation of the vehicle unsafe to be convicted of operating motor vehicle while under influence, but it must prove that it diminished his capacity to operate safely. The Appeals Court held that there was a substantial possibility of a miscarriage of justice warranting reversal due to the trial judge's giving of a jury instruction providing that a conviction for driving while under influence of intoxicating liquor was warranted if the defendant was influenced in some perceptible degree by intoxicating liquor, regardless of whether it impaired his ability to drive safely. A conviction for driving while under the influence of intoxicating liquor (DWI) may rest entirely on circumstantial evidence. A lay witness may testify to another's sobriety or lack of it.

However it may be error to allow a police officer to give opinion testimony that he believed the defendant's ability to operate a motor vehicle safely was impaired. There may also be a question as to whether a police officer, testifying to a lay opinion that the defendant was operating under the influence of alcohol, constitutes an opinion of guilt. The Appeals Court held that testimony from a police officer that the defendant was engaged in drug dealing constituted an opinion of guilt. Such testimony is unnecessary, and it tends to usurp the jury's function of drawing inferences from the facts.

The question of what constitutes diminished capacity is left for the jury. The jury is told to rely on their own experience and common sense about the effects of alcohol. They are told to evaluate all the believable evidence about the defendant's appearance, condition and behavior at the time, in order to determine whether the defendant's ability to drive safely was diminished by alcohol. The following are examples of faculties, the lessening of which may be considered in determining whether someone's ability to operate a motor vehicle is diminished:

  • Alertness
  • Judgment
  • Ability to respond promptly
  • Mental clarity
  • Self-­‐control
  • Reflexes

The Appeals Court has held that these are examples and not essential elements of impairment.The actual observations that might lead one to believe that the above faculties are affected might include one or more of the following:

  • Odor of alcohol
  • Red, glassy eyes
  • Slurred speech
  • Unsteady gait
  • Belligerence
  • Use of obscenities

Each of these may have one or more alternate causes other than intoxication.

Despite the public protection purpose of the statute, an operator who either feels the effects of the alcohol only after the operation has begun or realizes once behind the wheel that they should not be driving is not encouraged to pull over. The Appeals Court has taken the stance that a person who drinks alcohol is required to anticipate and ascertain his or her ability to operate a motor vehicle before attempting to do so, therefore seeking shelter because he thought he was under the influence of alcohol is not a defense. Such a stance seems both short-sighted and counter-productive as it assumes the operator has the background/knowledge to determine how they will feel at a later time and encourages the operator to continue on the roadway for fear of pulling over and getting arrested.

The timing of the consumption in relation to the driving may also be important. If the operator is found in the vehicle and there is evidence of consumption in or around the vehicle, it may be difficult to prove impairment at the time of driving. In Commonwealth v. Sudderth, evidence that police officers found defendant asleep in reclined position in driver seat of stationary car legally parked on public way, with car's engine running, and beer cans, some empty, in and around vehicle, did not warrant a reasonable inference that the defendant became impaired before rather than after he parked vehicle.

(Taken from Drunk Driving Defense in Massachusetts, pg. 35-38)