The Supreme Judicial Court of Massachusetts issued a decision earlier this week that challenges a fundamental assumption in our justice system – that running away from police is evidence of guilt.

The state’s highest court reversed Jimmy Warren’s conviction for gun possession and instructed judges to factor the effect of racial profiling into their decisions, at a time when police encounters with black men have become a political powder keg.

The groundbreaking ruling stems from a case of breaking and entering in 2011. Police in Roxbury responded to a call, received a general description from the victims, and began searching for three African-American men wearing hoodies. An officer driving around the neighborhood saw two black men who matched the description approached them because he had what he called a “hunch” they were the suspects.

Warren and the other man jogged away when the officer approached, and he pursued them, eventually searching Warren and finding a gun nearby that police attributed to him.

The key issue in the case was whether police had reasonable suspicion to stop and search Warren, says Northeastern University law professor Daniel Medwed.

“Under the 4th Amendment of the constitution, police may not engage in unreasonable searches and seizures. If they do so, then any subsequently obtained evidence is excluded from use at trial.”

Boston Police argued they had reasonable suspicion, and the trial court convicted Warren for gun possession. But the SJC had a different view of the information available to the police at the time and unanimously ruled it was not enough to support a stop—that it was too vague to rise to the level of reasonable suspicion.

"...running from police might simply reflect a desire to avoid the “recurring indignity” of being racially profiled."

“But really what makes this case groundbreaking and has garnered national attention” says Medwed, “is that the court essentially said that when an African-American male flees from law enforcement in the city of Boston, it’s not fair to create an inference of guilt.”

Instead, Justice Geraldine Hines wrote in the opinion, running from police might simply reflect a desire to avoid the “recurring indignity” of being racially profiled.

To support this point, Hines cited data from the ACLU and the Boston Police Department indicating young black men are stopped by police on the streets of Boston at a vastly disproportionate rate when compared with other people. The ACLU study found that between 2007 and 2010, 63% of police stops targeted blacks, who make up less than a quarter of the population.

Medwed sees two long-term impacts of the SJC’s decision could have on court cases. First, evidence of a black man running from police in Boston might not hold the same weight in determining reasonable suspicion as it once did. Second, prosecutors may be less likely to hold up flight evidence to the jury as a shorthand for guilt.

Now, says Medwed, “I envision every defense lawyer in the commonwealth citing the Warren case to say: this evidence is irrelevant, it doesn’t create an inference of guilt, and the jury shouldn’t even hear about it.”

Civil rights advocates have applauded the SJC’s decision, but Boston Police have criticized it, saying they don’t engage in racial profiling, and the Suffolk District Attorney has expressed his intention to ask for a rehearing of the case.

The data cited in the case is from several years ago, and maybe things have improved, says Medwed, but qualitative evidence suggests that racial profiling is still a problem on the streets of Boston.

“My hope is that this opinion, at least, will raise consciousness of profiling, and perhaps affect police practices going forward.”