The Massachusetts Supreme Judicial Court has sided with a white Boston police cadet in a controversial case that asked the court to decide if the department was wrong for refusing to hire the cadet after he failed a hair follicle drug test.

The state's high court ruled Wednesday in the case that without additional evidence, the use of the hair drug tests — which examine a person's hair for illicit substances — was not enough to prove that Michael Gannon should have been "bypassed for employment in 2013 after his hair tested positive for cocaine use in 2010."

In its ruling, the court deferred to the Civil Service Commission's judgment — confirming its discretion on the matter — on Gannon's complaint against the Boston police. The SJC agreed with the commission that "by itself, the Psychemedics hair drug test was not enough to sustain the department's burden of proving by a preponderance of the evidence that Gannon ingested cocaine." The court said the commission's "determination [in Gannon's case] was supported by substantial evidence."

As WBUR's Jerome Campbell previously reported in April:

In 2010, then-30-year-old Michael Gannon gave a hair sample for a drug test when he was applying to be a Boston police officer. The results came back positive for cocaine, and the department decided to not hire him. Gannon said he never did cocaine and previously had passed two other drug tests while in the cadet program. The day after he learned he failed the test, he voluntarily took another and passed. Still, the police department did not hire him. Gannon appealed the decision to the state's Civil Service Commission in 2012 and won. A crucial part of his defense relied on the testimony of a clinical pharmacologist who explained that the possibility of contaminated drug results was a reasonable concern. The commission also cited earlier decisions involving other Boston police officers where hair follicle test results varied too greatly to be considered reliable. However, a Massachusetts Superior Court overturned that decision in 2017, saying the Civil Service Commission overstepped its bounds.

An attorney for Gannon said Wednesday he needs to speak with his client before commenting on the ruling, but did confirm that because the ruling affirms the commission's findings, Gannon should move to the top of the department's hire list.

Questions around the reliability and fairness of hair follicle drug tests, as WBUR's Campbell also explained, have circulated for many years. In Boston, at least 10 other officers lost their jobs after testing positive for illicit drugs in hair tests. Several resulting lawsuits claimed the tests are racially discriminatory.

A federal Court of Appeals upheld a decision that found hair testing is biased against people of color. The decision referenced studies that found cocaine will bind in higher concentrations to the melanin in dark hair. That case involved several other officers who were terminated by the Boston Police Department (BPD) over hair samples that tested positive for illegal substances. Court documents show the city has paid out almost $2 million in back pay to four of those officers.

The ruling and the commission pointed to a study several times that discussed how the reliability of the tests could be affected by different hair types and ethnicities.

A spokesman for the Boston police declined to comment Wednesday, saying the department is still reviewing the court's decision.

Correction: A previous version of this story detailed Michael Gannon's race incorrectly. He is a white man. The post has been updated. We regret the error.