The Massachusetts Supreme Judicial Court has ruled that field tests currently used to test for alcohol impairment cannot be used to determine if a driver is impaired by cannabis.
In the ruling, Justice Frank Gaziano, pointed out that “there is no scientific agreement on whether, and if so, to what extent” the current field sobriety tests – such as the horizontal gaze nystagmus, walk and turn, and one leg stand tests – “are indicative of marijuana intoxication.”
“Some studies have shown no correlation between inadequate performance on FSTs and the consumption of marijuana; other studies have shown some correlation with certain FSTs, but not with others; and yet other studies have shown a correlation with all of the most frequently used FSTs,” he opined.
Moreover, Gaziano said that because cannabis affects individuals differently, and to what extent is not commonly known, “neither a police officer nor a lay witness who has not been qualified as an expert may offer an opinion as to whether a driver was under the influence of marijuana.”
The justices conclude that police officers “may not testify to the administration and results” of field sobriety tests in cannabis intoxication cases and that lay witnesses “may not offer an opinion that another person is ‘high’ on marijuana.”
The court ruled that while officers “may testify to observed physical characteristics” of drivers, such as “bloodshot eyes, drowsiness, and lack of coordination” officers are not permitted “to offer an opinion that these characteristics mean the driver is under the influence of marijuana.”
The case, COMMONWEALTH v THOMAS GERHARDT, will be moved back to District Court to continue, consistent with the higher court’s opinion.