D.C. prosecutors have filed additional charges against more than 200 protesters arrested during President Trump’s inauguration, continuing to drill down on suspects they believe smashed restaurant windows, set a limousine on fire and attacked the car’s driver.

While most of the protesters were initially charged with one count of felony rioting, a grand jury on Thursday returned a superseding indictment that added new charges: inciting or urging to riot, conspiracy to riot and counts of destruction of property.

On Friday in D.C. Superior Court, prosecutors also obtained their first felony conviction in the Jan. 20 riots. Dane Powell, 31, of Tampa, pleaded guilty to rioting and assault on a police officer, admitting he threw a large piece of concrete at the officer. Powell is set to be sentenced in July and faces up to three years in prison for each charge. His attorney could not immediately be reached for comment.

Meanwhile, it seems the first of the trials for alleged rioters won’t be until March 2018. During a separate Friday hearing before Judge Lynn Leibovitz, several defense attorneys said trials this year would not be feasible because they need time to pore over the 650 hours of video from police officer body cameras, cellphones and helicopter cameras. Leibovitz said she wanted to begin the trials as early as the fall and was concerned about waiting.

“These will be dragged out until everyone here are grandparents. Unless that is the goal,” she said.

Police fire pepper spray as protesters clash with police on K Street during the President Trump’s inauguration on January 20. (Photo by Ricky Carioti/The Washington Post)

Also at issue for lawyers is what information from the 188 cellphones confiscated from the protesters will be used by the government and what information will be shared with ­co-defendants. Defense attorneys have said they were concerned prosecutors could misuse information such as personal photos and videos that may not have anything to do with the riots.

Assistant U.S. Attorney Jennifer Kerkhoff said her office planned to identify each video, text message and email obtained that they believe directly links each defendant to the riots, as well as where each video was shot.

Kerkhoff told the judge her office remained in plea discussions with the defendants and their attorneys. In addition to Powell, prosecutors said two other defendants have pleaded guilty. Those cases involved misdemeanor charges.

Prosecutors also said they had dismissed charges against three additional defendants.

Only about 20 of the 200 or so co-defendants had their arraignment on the new charges Friday because the full group is too large to fit in one courtroom. The remainder, broken up into groups of about 20 to 30, will have their arraignments in the coming weeks.

[Inauguration Day’s mass arrests are challenging for prosecutors]

Prosecutors allege that the protesters employed “black bloc” tactics, most commonly linked to anarchists.

The rioters, wearing all black, armed themselves with hammers, crowbars, metal poles, wooden sticks and other items, prosecutors said. They said the protesters wore masks and goggles to hide their faces.

The indictment includes a nearly minute-by-minute timeline of the movements of the group on Jan. 20.

For instance, prosecutors allege that at 10:30 a.m., two defendants broke out the windows of a limousine parked on K Street Northwest and assaulted its driver.

Five minutes later, according to the indictment, four other defendants broke the windows of a Bank of America branch located in the 1200 block of I Street NW.

The rioting, prosecutors said, lasted about 30 minutes and occurred within 16 city blocks. Six officers were injured.

In the new indictment, prosecutors charged three people for the first time in the case.

One of them, Dylan Petrohilos, a 28-year-old graphic designer, was charged with rioting, conspiracy and multiple counts of destruction of property.

In an interview with The Washington Post this month, Petrohilos said officers broke through the door of his Petworth home early April 3. Police were led to the house after an undercover police officer secretly attended protest-planning meetings in the weeks before the Jan. 20 inauguration, court documents show.

Petrohilos declined to comment on the charges. He referred calls to the District activist group, Dead City Legal Posse. Sam Menefee-Libey, an activist with the organization called the charges “outrageous” and said the charges were “the criminalization of dissent.”

[D.C. police infiltrated inauguration protest]

One defense attorney involved in the case argued that prosecutors are unfairly targeting the demonstrators.

“The superseding indictment is sheer government abuse of power,” Jason Flores-Williams said. “They are prosecuting people not based on evidence, but for who they know and who they associate with. It’s unconstitutional and repressive.”

The additional charges were based on evidence gathered during an ongoing investigation by prosecutors and D.C. police.

Perry Stein contributed to this report.