'Justice for J6' updates: Sparse crowd met with massive police presence at rally

The "Justice for J6" rally wrapped up Saturday afternoon after about an hour of speeches, without any major known incidents.

Authorities had warned of possible threats of violence at the event, and Capitol Police officers could be seen in riot gear standing on the perimeter of the crowd as people gathered in front of the U.S. Capitol.

Metropolitan Police Department Chief Robert Contee also said in a video message Saturday that the department had security "covered" for the event and was ensuring that people could "peacefully express their First Amendment rights."

Capitol Police said they arrested a man for a weapons violation shortly before the rally kicked off. He allegedly had a knife. Additional details were not immediately available.

No other arrests have been reported at this time.

The Capitol Police Civil Disturbance Unit also responded to a group of protestors and counterprotestors near the Capitol and "separated the groups without incident," police said.

Right before the rally kicked off, Capitol Police say they arrested a man with a knife for a weapons violation. 

The arrest happened at 12:40 p.m., authorities said. No other details were immediately provided.

Knives are one of over a dozen prohibited items and activities on Capitol Grounds, along with firearms, mace, ammunition and other items.

In the days leading up to the rally, DC Police posted signage in the area of the rally that stated: "All firearms prohibited within 1000 feet of this sign."

Rally organizer Matt Braynard laid out "some ground rules" at the start of the protest, urging the crowd to be respectful of law enforcement.

"There are uniformed officers here who I demand that you respect, you are kind to, you're respectful to and you're obedient to," he said. "They're here to keep us safe."

He condemned the violence of the insurrection while calling for transparency in the investigation of the Jan. 6 riot.

 "Anybody who engaged in that kind of violence or property destruction that day deserves to be tried with a speedy trial," he said.

"This is about the many people who were there that day who have not been charged with violence, not been accused of assaulting a police officer or destroying property and the disparate treatment they received," he continued.

At least 610 people have been federally charged in connection with the insurrection. About 60 remain behind bars, most of whom are suspects prosecutors and judges have identified as posing a credible threat to public safety based on either their alleged violent assaults against police or role in planning the riot.

-ABC News' Alexander Mallin

Counterprotesters could be seen gathering near the Capitol ahead of Saturday's rally, toting signs and flags.

One man had a hand-painted sign with the word "Loser" on it, which he told the Associated Press referred to former President Donald Trump. 

A woman could also be seen carrying Black Lives Matter flags. 

It is unclear how many protesters and counterprotesters will show up for the event, though organizers have secured a permit for 700 attendees.