The Massachusetts Supreme Judicial Court ruled today that field sobriety tests used to determine if someone is drunk cannot be legally used as conclusive evidence that a motorist is under the influence of marijuana.
According to the Associated Press, 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. However, the court ruled that 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. The ruling came in a case of Thomas Gerhardt, who was charged with impaired driving in 2013.
The court noted there currently is no reliable scientific test for marijuana impairment comparable to tests for blood alcohol content. In drunken-driving cases, results of field sobriety tests can be correlated with blood alcohol readings as evidence of impairment. The lack of such a test for marijuana has taken on greater significance in states such as Massachusetts that have legalized the recreational use of marijuana for adults, but where driving under the influence of cannabis remains a serious crime.