Police in riot gear contain a group of protesters at the corner of 12th and L Streets NW on the day of the inauguration of Donald Trump as president of the United States in Friday, Jan. 20, 2017. (Jahi Chikwendiu/The Washington Post)

For six demonstrators who joined hundreds of others in Washington for an Inauguration Day protest that turned chaotic and destructive, their trial in D.C. Superior Court, set to resume Monday, seems to hinge on an issue of perception:

Did the blocks-long march and related mayhem in downtown Washington amount to a riot? Or was it a lawful, free-speech assembly in which a relatively small number of participants committed vandalism, including smashing windows and spray-painting a government vehicle?

As the jury in the case heard opening statements and witness testimony early last week — before the trial recessed Tuesday for Thanksgiving — lawyers for the two sides offered starkly different perspectives of the glass-shattering disturbance on the day President Trump was sworn in.

Assistant U.S. Attorney Jennifer Kerkhoff cast the Jan. 20 demonstration as a premeditated mass assault on the city’s peace and safety — a protest geared entirely toward “violence and destruction,” she said. Attorneys for the four women and two men on trial described a constitutionally protected gathering of political dissenters, “only a small handful” of whom “engaged in violence or engaged in destruction,” as one lawyer put it.

In a trial that is expected to last until mid-December, how the jurors ultimately view the raucous events of Inauguration Day will not only determine the outcome of the current case but also could influence how prosecutors handle the cases of more than 150 additional protesters charged in the 33-minute disturbance.

Like the six anti-Trump activists who are in court now, the other demonstrators face felony rioting charges, and the U.S. attorney’s office has said it is planning for a series of trials extending into the middle of next year, with the defendants being prosecuted in groups of about a half-dozen. However, if the first trial ends with acquittals, it could prompt the government to rethink its approach to the rest of the cases.

On that damp, chilly morning, hundreds of demonstrators, gathered under the banner “Disrupt J20,” marched about a mile from Logan Circle to the Franklin Square area, most of them clad in dark clothing and with their faces hidden — a civil disobedience tactic called “black bloc.” Along the way, and during a circuitous march covering several blocks near Franklin Square, protesters left a trail of wreckage.

Legally speaking, rioting in the nation’s capital can entail collective responsibility, and that concept is at the heart of the ongoing trial, in which none of the defendants is accused of personally causing any damage or injuries.

The District’s criminal code defines a riot as “a public disturbance involving an assemblage of 5 or more persons which by tumultuous or violent conduct . . . creates grave danger of injury to property or persons.” If anyone is seriously hurt or the damage exceeds $5,000, “every person who willfully incited or urged others to engage in the riot shall be punished by imprisonment for not more than 10 years.”

A D.C. police officer suffered a broken wrist in a half-hour of mayhem that authorities said caused more than $100,000 in damage.

In her opening statement, Kerkhoff did not cite any direct evidence that the defendants “willfully incited” others to engage in rioting — and defense lawyers stressed to the jury that no such evidence exists.

The prosecutor pointed out the six could have quit the march when the violence began. Video clips show the defendants in the group at various times during the disturbance, Kerkhoff said.

It appears she will argue at trial that their continued presence in the unruly, chanting crowd amounted to incitement.

Besides being charged with inciting a riot, the defendants are accused of conspiracy to riot, even though Kerkhoff did not mention any direct evidence that the six took part in planning the protest. Again, defense lawyers said the government has no such evidence.

In the days before the inauguration, authorities said, undercover police officers infiltrated meetings of Disrupt J20 at which mayhem was planned.

Kerkhoff told the jury the march was widely publicized in advance, including the intended use of the black bloc tactic, which is associated with riotous demonstrations.

“This was not some sort of spontaneous gathering,” she said in court. “There were advertisements . . . ‘Come to Logan Circle. Wear black.’ ” Kerkhoff noted the six showed up with dark clothing, goggles, helmets and other black bloc paraphernalia.

The six activists also are charged with destruction of property and with engaging in a riot, which is punishable by up to six months in jail.

The U.S. attorney’s office declined to comment on the aggressive prosecution, which the American Civil Liberties Union in the District criticized as excessive.

“From what we can tell, this seems like a gross overreach, with the prosecution trying to convict nearly 200 people for crimes that were committed by a few,” said Arthur Spitzer, legal director of the ACLU’s District branch. The group has a pending lawsuit against the city, accusing police of arresting innocent protesters on Inauguration Day and detaining people for up to 16 hours without food, water and bathrooms.

“Unless they have some evidence that we don’t know about showing an agreement among all these people to engage in acts of vandalism, then we think these prosecutions are abusive,” Spitzer said of the current trial.

For the charges to stick, jurors will have to conclude the protest was a riot.

To that end, Kerkhoff, in her opening, tried to give the panel an intimate view of the chaos, from the vantage point of terrified workers and customers in a BP gas station, an Au Bon Pain cafe, a Starbucks and other places where windows were smashed. The video clips she showed the jury were mostly close-ups, from cellphones and body-worn police cameras, conveying a sense of perilous, frenetic violence.

As several brick-throwing demonstrators smashed windows at the gas station, the “frightened” employee inside “puts a case of drinks up against the door to prevent people from coming inside and attacking,” Kerkhoff said.

The owner of a sandwich shop had to temporarily close her business because of vandalism. “She bore the stress of that,” the prosecutor said. At the Starbucks, workers and patrons “had to dive for cover” against “flying glass” as protesters hurled bricks and a trash can, shattering a plate-glass window.

On TV monitors in the courtroom, Kerkhoff showed the jury the repair bill for a large window at the Au Bon Pain: $5,790.40, the invoice read.

“In my mind, there was no stopping what was going on,” a D.C. police officer, Ashley Anderson, testified. She joined the force about four years ago and is assigned to a bicycle patrol squad. Trying to corral the demonstrators that day, “I honestly felt hopeless,” she told the jurors. “It was like something I had never seen before, ever.”

Defense lawyer Steven McCool, representing one of the men on trial, showed the jury a long-range video clip — an aerial shot of 13th Street NW as the huge crowd of protesters moved south toward Franklin Square. A handful of demonstrators — just specks on the video — broke away from the throng to vandalize the gas station, then rejoined the group as it kept marching.

“A couple of people run toward the BP station,” he said in a dismissive tone. “They would have you believe that this . . . shows you a riot was occurring.”

He told the jury: “This case is about our freedom to associate with one another and to express our opinions freely. . . . We are here because it’s easier for the police to treat everyone the same, to call a protest a riot and lock everybody up. It’s easier to do that than to comply with the First Amendment.”

Five defense lawyers followed him in making opening statements, all sounding a similar theme: Their clients are activists, not criminals.

One of them, Brittne Lawson, 27, is a nurse who works with cancer patients at the University of Pittsburgh Medical Center. “They have no evidence that she did anything wrong,” her attorney said.

Another defendant, Alexei Wood, 37, of San Antonio, is a photojournalist who was documenting the march and live-streaming it on Facebook.

“Mr. Wood was not involved in that,” his lawyer said of the mayhem. “He’s independent, he’s up-and-coming, and he’s building a résumé.”

He wasn’t inciting “what they call a riot.”