In September 2017, the Massachusetts Supreme Judicial Court unanimously ruled that police cannot give testimony that, in the officer’s opinion, a driver was under the influence of marijuana based on their on-scene observations, including sobriety tests.
The court found that there is no consensus in the scientific community that roadside sobriety tests prove someone is under the influence of marijuana. The judges noted that the effects of marijuana “vary greatly from one individual to another, and those effects are as yet not commonly known.”
Accordingly, the court ruled that “neither a police officer nor a lay person who has not been qualified as an expert may offer an opinion as to whether a driver was under the influence of marijuana.”
Police may still testify about their objective observations of a driver, including the odor of burnt marijuana and performance on field sobriety tests. But they may not refer to those tasks as “tests,” say that a driver “failed,” or testify that they believed driver was “high.”