When Henry Louis Gates Jr., a prominent Harvard professor of African-American studies, was arrested for disorderly conduct by a white Cambridge police officer last summer, President Obama led a chorus of critics denouncing the local police department.

Gates, who is African-American, described his arrest as a “teaching moment” about race relations in America. His case drew national attention to the relationship between policing and race -- Obama wound up hosting Gates and the officer who arrested him for a so-called beer summit at the White House. And the arrest, for some, raised the question of whether officers disproportionately arrest blacks for disorderly conduct, considered one of the most discretionary – and most abused – charges in the nation’s criminal justice system.

But a review of the Cambridge department’s handling of disorderly conduct cases from 2004 to 2009 finds no evidence of racial profiling. Instead, the analysis by the New England Center for Investigative Reporting finds that the most common factor linking people who are arrested in Cambridge for disorderly conduct is that they were allegedly screaming or cursing in front of police.

Of the 392 adults arrested for disorderly conduct, 57 percent were white and 34 percent were black. That racial breakdown almost exactly mirrored the racial composition of the population that Cambridge police investigated for disorderly conduct, the NECIR analysis shows. Cambridge is 68 percent white and 12 percent black, the latest U.S. Census data shows.

But multiple racial profiling experts said the fairest way to analyze the Cambridge police department's conduct was to compare the racial makeup of those charged to that of those investigated, and not to the racial makeup of the overall population.

The most striking conclusion of the review of Cambridge police data is that the majority of those arrested for disorderly conduct were allegedly yelling - often screaming obscenities – in front of police before the handcuffs snapped shut. More than 60 percent of the disorderly arrests reviewed by NECIR involved some sort of allegedly inflammatory speech, such as talking back to the police, more commonly known as “contempt of cop.”

A substantial minority of those arrested for the crime also shared another trait: 17 percent of them were homeless.

Civil rights advocates around the nation are increasingly concerned that disorderly conduct charges are being used to muzzle free speech. David G. Twohig, an attorney with the state public defender’s office, said that rather than race, his clients complain that their anger is what gets them in trouble with the law.

“Disorderly is often used when people do something to piss off the cops,” said Daniel Beck, a veteran criminal defense attorney in Cambridge.

“Sometimes, they’re just being a drunken jerk yelling,” he said. “Often, they’re challenging the cops’ authority."

Last month, the American Civil Liberties Union sued the Pennsylvania state police, arguing that officers had wrongly charged hundreds of people with disorderly conduct for swearing. The case is pending. 

And a Washington D.C. lawyer, who was arrested for disorderly conduct last summer after allegedly shouting “I hate police” to a group of officers, is currently seeking to get his arrest expunged.

Last fall, meanwhile, a man won a $50,000 settlement from the city of Pittsburgh, after he got into a dispute with a police officer over a parking space and made an obscene gesture.

In Cambridge, Nancy J. Berberena said she was arguing with a Cambridge officer when she was arrested for disorderly conduct in 2008. Berberena, 39, was distraught with the way the officer was questioning her son because he resembled a suspect in another crime.  She said the officer swore at her, telling her to keep quiet, and pointed his finger close to her face.

When she returned both the curse and finger-pointing, she was arrested for assault and battery on a police officer and disorderly conduct.  She denies she did either.

“We were trying to protect ourselves with words,” Berberena said.

Both charges were later dismissed by the prosecutor, court records show.

The Gates controversy began last July, when Crowley arrested Gates for disorderly conduct outside his home, after responding to a dispatcher’s call about a potential break-in at the house. According to the police report, Gates became uncooperative during the incident.  “Is this how you treat a black man in America?” Gates recalled yelling at the time. 

When Crowley asked to speak with him outside his home, Gates replied, “Ya, I’ll speak with your mama outside,” according to the police report.

Cambridge Police Commissioner Robert C. Haas, who declined to comment on the Gates case, said that speech is never the sole basis for an arrest.

“You have a situation where you are trying to stop behavior, and entangled in that behavior you have people saying things,” he said.  “It’s the behavior officers are trying to deal with and it’s the behavior that officers are trying to stop that they believe really creates social disharmony. They have an obligation to stop it.”

Haas called the Gates incident “a major crisis” for his department. He said his department conducted a study of its use of disorderly conduct charges between 2004 and 2008.  The analysis, which also concluded race was not an issue, will be posted on the department’s website.

Sgt. James Crowley, who arrested Gates, said in a written statement that the findings clear him and his department of racism.

“I have never and will never use race to affect how I do my job,” he said.

Experts cautioned the findings don’t prove Gates was wrong in raising the race issue, saying that it isn’t possible to determine from a statistical analysis whether conscious or unconscious bias played a role in the interaction between Gates and Crowley.

“Race can still play a role in any particular encounter between a police officer and a citizen even if we find a clean bill of health on the numbers for Cambridge and disorderly conduct enforcement,”  said David A. Harris, a leading authority on racial profiling who teaches at the University of Pittsburgh School of Law.

Gates declined to comment for this story, referring questions to his lawyer, Harvard Law Professor Charles Ogletree. Ogletree is currently promoting a new book about racial injustice, entitled “The Presumption of Guilt: The Arrest of Henry Louis Gates Jr. and Race, Class and Crime in America.” In it, he compares the Gates’ arrest to the 1991 beating of Rodney King in Los Angeles, which led to race riots.

Ogletree said his book was a broader-based look at racial injustice and class issues, and was not specifically about the Gates case. He said he did not request any arrest data from the Cambridge Police nor did he interview police officials or Sgt. Crowley.

“This is not about data and Cambridge,” he said.

In almost every way, the Gates case was an aberration for the Cambridge department, records show. Gates, 59, was one of the 10 oldest people arrested for disorderly conduct in the last five years in Cambridge. He was one of fewer than two dozen people arrested at their homes. And he was the only person arrested by Crowley for disorderly conduct between 2004 and 2009.

The main similarity between Gates and others’ arrested for disorderly conduct was his fury at the police. But unlike Gates, whose case was quickly dropped by prosecutors, others were not so lucky. What might seem like a minor incident can leave people with a permanent criminal record, forever affecting their ability to find a job.

“I was under the impression it wasn’t available after a certain amount of time, like two years,” said a 31-year-old white male professional in Boston who was arrested in October 2007 after a day of celebrating a Red Sox victory with his buddies.  “But it’s out there.  It’s public.”

The man, who requested his name not be used because he was embarrassed, had left a Harvard Square bar at 1 a.m. and begun tipping over plastic newspaper boxes.  

While his friends picked up the news boxes, he challenged the officer to chase him.  He said:  “(expletive) you, catch me if you can, go have a doughnut!,” referring to a stigma surrounding police that they overindulge in doughnuts on the job.

The man acknowledged he was being a “jerk” but said he was not doing anything to endanger or annoy the public, which is a legal requirement of the disorderly conduct law.  His friends picked up the news boxes and when he started running away, police cars surrounded him on the street.

“A whole bunch of cops swarmed around me and threw me against the car,” the man said.  

He spent eight hours in jail and later paid a $200 fine to dispose of the case, he said.

“People were up there for much more serious crimes and here I was up there for swearing,” he said about his hearing in Cambridge District Court a few days after the arrest.

The Gates arrest prompted changes at the Cambridge police department. Now, every time officers charge someone with disorderly conduct, they must thoroughly document why they made the arrest. Officers are also receiving training intended to make them more aware of how they react when citizens get angry at them.

Two other reviews sparked by the Gates arrest are underway in Cambridge.  This summer, a 12-member committee of law enforcement experts and academics from around the country plans to release its analysis of “lessons learned” from the incident. And the city’s Police Review Advisory Board, a civilian oversight review board, has completed a preliminary investigation of the incident but has not yet released its findings.

The New England Center for Investigative Reporting is a nonprofit investigative reporting newsroom based at WGBH and Boston University’s College of Communication. Center codirector Joe Bergantino contributed to this report, as did BU students Sarah Favot, Christine Savage, Jaime Lutz, and Sydney Lupkin.