BOSTON — Massachusetts’ highest court ruled Tuesday that field sobriety tests typically used in drunken-driving cases cannot be treated as conclusive evidence that a motorist was operating under the influence of marijuana.
The Supreme Judicial Court said it was reasonable for police officers to testify — as non-expert witnesses — only to their observations about how individuals performed during sobriety tests. But officers are not allowed to tell juries if defendants passed or failed such tests, nor offer their own opinions on whether a driver was too high to be behind the wheel.
STATE BY STATE: Massachusetts Cannabis News
The ruling came in a case of a man who was charged with impaired driving in 2013.
The justices noted there currently is no reliable scientific test for marijuana impairment comparable to tests for blood alcohol content, though several potential tools are under development. In drunken-driving cases, results of field sobriety tests can be correlated with blood alcohol readings as evidence of impairment.
