Adam Kokesh and libertarian activists expected to provoke a police response when he posted a video of himself apparently loading a shotgun on Freedom Plaza in violation of D.C. law on the Fourth of July, but it arrived on his doorstep with an overwhelming boom Tuesday night.

A U.S. Park Police SWAT team and other officers knocked on the door of his single-family home on a quiet Herndon cul-de-sac, then kicked the door in and tossed a flash grenade into the foyer as police helicopters whirled overhead, his roommates said.

The rabble-rouser and Iraq war veteran who promised “we will not obey” on the video and has advocated for overthrow of the government “by whatever means necessary” was removed in handcuffs and charged with possession of hallucinogenic mushrooms while possessing a firearm, according to court papers. His housemates allege that they were mistreated by police, who they say used too much force.

Park Police Lt. Pamela Smith said the agency has “chosen not to respond” to those allegations because of the ongoing investigation. Park Police also would not comment on the roommates’ characterization of what happened inside the home. It was unclear if charges would be filed related to the July 4 video on YouTube.

Smith would say only that her agency executed a search warrant at a Snowflake Court home about 7:45 p.m. Tuesday, looking for an unspecified weapon. The agency is responsible for policing Freedom Plaza, the park a few blocks from the White House where Kokesh filmed his video.

One roommate who saw the search warrant said police were looking for the gun and raw footage from the July 4 video. The housemates say officers took that weapon, files and other items.

On Wednesday, a Fairfax County court clerk said Kokesh declined to be arraigned or fingerprinted. A judge went to Kokesh’s county jail cell to arraign him, said Lt. Steve Ebert of the sheriff’s office.

Four housemates, who work on Kokesh’s Internet show “Adam vs. the Man,” said police barricaded the street with cruisers and a light armored vehicle Tuesday night. Darrell Young, a roommate who was driving home, said he watched the action unfold.

“I instantly knew it was going to be a raid,” Young said.

As roommates cooked dinner and Kokesh napped, several of the residents heard a thump at the door. Then another knock. Finally, the door burst open, the flash grenade was lobbed inside and the house filled with smoke.

Officers poured in. Kokesh was separated from the housemates, who were handcuffed and herded into a room, they said. They estimated that 30 to 40 officers partici­pated in the raid.

Over the next five hours, the roommates said, officers combed through the house, looking through books, emptying closets and cracking a safe owned by Ko­kesh.

They said Kokesh was questioned and kicked at one point. Another claimed that he was hit. “I was punched in the back of the head,” Edward Yealey said.

In the July 4 video, Kokesh is seen loading rounds into what appears to be a shotgun as the Capitol looms in the distance.

“We will not be silent. We will not obey,” Kokesh intones. “We will not allow our government to destroy our humanity. We are the final American Revolution. See you next Independence Day.”

When Kokesh posted the video, D.C. police and U.S. Park Police said they would investigate, because it is illegal to carry a loaded weapon in public in the District. It came in the wake of his plan to lead a march of gun-toting people from Arlington County to the District, which he later canceled.

Steven D. Silverman, a defense lawyer from Baltimore and a former public defender, said he thought that authorities used proper force. “I frankly don’t find it unusual or unreasonable based on the public, volatile comments and actions this person has demonstrated,” Silverman said.

It wasn’t the first encounter with the law for Kokesh.

In six years of headline-grabbing activism, he has embraced causes including peace in Iraq, free speech in the United States and the unsuccessful 2012 presidential candidacy of Ron Paul. He has invoked Mahatma Gandhi and the First Amendment, and he’s used both dancing and loaded weapons to make his point.

“We will continue to spread the message of liberty, self ownership, and the non-aggression principle regardless of the government’s relentless attacks on our operation,” said a statement posted on Ko­kesh’s Web site on Wednesday.

In 2007, Kokesh was arrested at the Hart Senate Office Building wearing a T-shirt that read “Iraq veterans against the war.” He was arrested again in 2011 when he led a group dance party at the Jefferson Memorial. He has gotten into trouble for protesting in a Marine uniform and for taking a souvenir gun home from the battlefield.

David Benowitz, a defense lawyer in the District, said that should police decide to file charges linked to the Freedom Plaza incident, they might not have to prove that a weapon seized from the Herndon house is the gun in the video.

“If they seize a Mossberg in Virginia and it looks like the Mossberg in the video, the government could certainly say it’s evidence of guilt in D.C.,” Benowitz said.

On Wednesday afternoon at the home, a reporter was greeted by Yealey, who was wearing a handgun strapped around his waist.

The roommates described themselves as voluntaryist, a strain of libertarianism that believes all acts — such as paying taxes — should be voluntary. They said they are nonviolent but believe the government has a monopoly on power.

They were still reeling from the raid.

“It was a pure act of intimidation,” said one roommate, who identified himself only as Jeremy.

William Branigin, Aaron C. Davis, Peter Hermann and Martin Weil contributed to this report.