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Massachusetts Motor Vehicle Homicide Conviction overturned: Expert Testimony or Merely an Opinion?


  Expert testimony is critical in a Massachusetts Motor Vehicle Homicide prosecution.  The issue of whether this testimony is admissible came up in the trial of Commonwealth v. Guinean, which was recently decided by the Massachusetts Court of Appeals.

Back in 2010, the defendant was found guilty of both OUI and motor vehicle homicide.  On appeal, the defense lawyer claimed that a Superior Court judge abused his discretion in admitting expert testimony introduced by the Commonwealth. The expert testimony was in relation to the computer-assisted power steering mechanism within the defendant’s motor vehicle.

Conviction Overturned because Expert Testimony was Improperly Admitted

After further consideration and appeals by the defendant, conclusions were made that the trooper merely stated his opinion and generally lacked the qualifications necessary to testify regarding the computer system within the vehicle. Because this information was central to Guinan’s defense, the Massachusetts Appeals Court overturned the OUI and motor-vehicle convictions.

OUI or a Vehicle Mishap?

Police officers were able to identify five beer cans in the car upon arrival to the scene of the crash, with only one of these cans identifiable as an open alcoholic beverage. The defendant, originally convicted of an OUI, had a blood alcohol level of only .06 percent (which is below the legal limit). The defendant also regularly took prescribed Vicodin for pain related to his gall bladder.

It is important to note that the combination of alcohol and Vicodin, when taken simultaneously, has the ability to impair an individuals ability to drive. While the defendant appeared disoriented when waking up at the hospital, it was later discovered by a neurologist that the defendant suffered from a “brain sheer”, a traumatic brain injury that frequently causes patients to exhibit symptoms such as agitation and disorientation.

Good Use of Medical Evidence by the OUI Lawyer

The OUI lawyer in this case used expert testimony to present a medical defense on the issue of impairment as it was argued that what appeared to be intoxication was a brain sheer.  This use of medical evidence can be important in any OUI case to dispute the officer’s opinion that the motorist was impaired.

A major issue lingering in the case was whether or not the defendant’s vehicle, a 2011 Hyundai Sonata, played a role in the fatal crash. After the collision, a recall was announced regarding the steering column and universal joint connections. Originally, trooper George testified that there was no mechanical failure in the steering mechanism and that it was properly installed. The state trooper attended vocational high school and had worked as an automobile mechanic and a tow truck driver before accepting a job with the North Attleboro Police Department. Upon obtaining a job with the state police, he endured extensive training and experience as an accident reconstruction specialist.

Expert Testimony and Discretion of A Judge

 In summation, while the trooper had a background in automobile mechanics, he was unable to identify any training or experience in computer science, computer software, nor computer systems. As the other evidence presented against Guinan was underwhelming and the troopers testimony was no longer credible, the appeals court overturned the original decision against Guinan, and noted that Trooper Georges’ testimony was hearsay evidence or simply an opinion.  While a judge typically has broad discretion regarding the admission of expert testimony, the expert, presented by the Commonwealth, must have extensive education and training in order to produce an “expert opinion”. The judge has the ability to abuse his or her discretion, by allowing an individual to testify regardless of whether or not they meet these qualifications.

To learn more about this case view a complete case summary on the Massachusetts Cases website here.

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