The FBI opened a “domestic terrorism” investigation into a civil rights group in California, labeling the activists “extremists” after they protested against neo-Nazis in 2016, new documents reveal.

Federal authorities ran a surveillance operation on By Any Means Necessary (Bamn), spying on the leftist group’s movements in an inquiry that came after one of Bamn’s members was stabbed at the white supremacist rally, according to documents obtained by the Guardian. The FBI’s Bamn files reveal:

The FBI investigated Bamn for potential “conspiracy” against the “rights” of the “Ku Klux Klan” and white supremacists.

The FBI considered the KKK as victims and the leftist protesters as potential terror threats, and downplayed the threats of the Klan, writing: “The KKK consisted of members that some perceived to be supportive of a white supremacist agenda.”

The FBI’s monitoring included in-person surveillance, and the agency cited Bamn’s advocacy against “rape and sexual assault” and “police brutality” as evidence in the terrorism inquiry.

The FBI’s 46-page report on Bamn, obtained by the government transparency non-profit Property of the People through a records request, presented an “astonishing” description of the KKK, said Mike German, a former FBI agent and far-right expert who reviewed the documents for the Guardian.

The report ignored “100 years of Klan terrorism that has killed thousands of Americans and continues using violence right up to the present day”, German said. “This description of the KKK should be an embarrassment to FBI leadership.”

Shanta Driver, Bamn’s national chair, criticized the investigation in a statement to the Guardian, saying, “The FBI’s interest in BAMN is part of a long-standing policy … Starting with their campaign to persecute and slander Dr. Martin Luther King, they have a racist history of targeting peaceful civil rights and anti-racist organizations, while doing nothing to prosecute the racists and fascists who attacked Dr. King and the movement he built.”

The FBI launched its terrorism investigation and surveillance of Bamn after white supremacists armed with knives faced off with hundreds of counter-protesters, including Bamn activists, at a June 2016 neo-Nazi rally in Sacramento. Although numerous neo-Nazis were suspected of stabbing at least seven anti-fascists in the melee, leaving some with life-threatening injuries, the FBI chose to launch a inquiry into the activities of the leftwing protesters.

The documents, though heavily redacted, did not include any conclusions from the FBI that Bamn violated laws or posed a continuing threat. Its members have not faced federal prosecution. The FBI declined to comment on Bamn.

“It’s clear the FBI dropped the investigation having no evidence of wrongdoing. It never should have been opened in the first place,” Driver said.

The 2016 rally was organized by two white supremacist groups: the Traditionalist Worker party (TWP) and an affiliated California entity, the Golden State Skinheads. California law enforcement subsequently worked with the neo-Nazis to identify counter-protesters, pursued charges against stabbing victims and other anti-fascists, and decided not to prosecute any men on the far-right for the stabbings.

The FBI appeared to have adopted a similar approach. In a redacted October 2016 document, the FBI labeled its Bamn investigation a “DT [domestic terrorism] – ANARCHIST EXTREMISM” case. The FBI’s San Francisco office wrote that it was investigating allegations that “members of Bamn attended a Ku Klux Klan rally and assaulted a Nazi supporter”. It summarized the Sacramento incident this way:

In 2016, law enforcement learned that the Ku Klux Klan would be holding a rally at the State Capitol Building … The KKK consisted of members that some perceived to be supportive of a white supremacist agenda. In response, a number of groups mobilized to protest the rally. Flyers were posted asking people to attend in order to shut down the rally.

The KKK and Traditionalist Worker party have similar ideologies but are distinct groups. It’s unclear why the FBI labeled the rally a KKK event.

The FBI’s report also appeared to obfuscate details about the political affiliations of stabbing perpetrators and victims, saying: “Several people were stabbed and hospitalized.” That’s despite the fact that California police investigators reported that neo-Nazis were seen on camera holding knives and fighting with counter-protesters (who suffered severe stab wounds).

The FBI file said its research into Bamn found that the group “lawfully exercised their First Amendment rights by engaging in peaceful protests”, but added that its “members engaged in other activity by refusing to disperse, trespassing in closed buildings, obstructing law enforcement, and shouting during and interrupting public meetings so that the meetings could not continue”.

Bamn has long advocated for racial justice and immigrants’ rights, frequently protesting at public events and organizing rallies.

The FBI report said it was “possible the actions of certain BAMN members may exceed the boundaries of protected activity and could constitute a violation of federal law”.

The “potential violations of federal law”, the FBI said, included “conspiracy against rights” and “riots”. The FBI cited Bamn’s website, which encouraged supporters to protest against the KKK, featured slogans like “SMASH FASCISM!” and “NO ‘FREE SPEECH’ FOR FASCISTS!”, and celebrated the “mass, militant demonstration” that “shut down” the neo-Nazi rally. The FBI also included screenshots of Bamn pages that referenced a number of the group’s other advocacy issues, including campaigns against “rape and sexual assault” and “police brutality”.

The FBI files further included mentions of Yvette Felarca, a Bamn member who was stabbed at the rally, but is now facing state charges of assault and rioting. (Her lawyers have argued in court that the police investigators and prosecutors were biased against anti-fascists and worked to protect neo-Nazis).

Bloody bandages and protest signs lie on the lawn of the California State Capitol after the rally. Photograph: Max Whittaker/Reuters

Driver, who is also Felarca’s attorney, said the FBI should have mentioned that Felarca was “stabbed and bludgeoned by a fascist in Sacramento”. She added: “Instead of finding the person who assaulted anti-racist protesters, the FBI chose to target BAMN, which by their own admission holds demonstrations that are protected by the First Amendment.”

The bureau’s justifications of the investigation and surveillance were disturbing, said Ryan Shapiro, executive director of Property of the People. “The FBI discovered that these protesters once shouted at a meeting and somehow that evidence was mobilized to support a full-fledged terrorism investigation,” he noted.

In November 2016, the FBI engaged in surveillance of a protest outside the Berkeley school district, according to the Bamn files. Due to the redactions, it’s unclear whom the FBI was watching, though the report noted that the FBI observed “several children … sitting outside … with signs next to them”.

The FBI report said its investigation and surveillance were not “intended to associate the protected activity with criminality or a threat to national security, or to infer that such protected activity itself violates federal law”. The report continued:

However, based on known intelligence and/or specific, historical observations, it is possible the protected activity could invite a violent reaction towards the subject individuals or groups, or the activity could be used as a means to target law enforcement. In the event no violent reaction occurs, FBI policy and federal law dictates that no further record be made of the protected activity.

Property of the People’s records requests broadly sought FBI documents on anti-fascists. The FBI did not release additional Bamn records beyond 2016.

The FBI’s insinuation that Bamn’s actions could provoke violence was odd, said German, the former FBI agent, who is now a Brennan Center fellow. He noted that it was white supremacists “who have used this tactic for decades” and said the violent provocations of rightwing groups were well known when he worked on domestic terrorism for the FBI in the 1990s. The Bamn report, he said, gave the “appearance of favoritism toward one of the oldest and most active terrorist groups in history”.

He added that the report should have made clear that the “KKK consists of members who have a bloody history of racial and antisemitic violence and intimidation and is known for staging public spectacles for the specific purpose of inciting imminent violence”.

Asked whether the Bamn investigation was ongoing and whether the FBI had opened any equivalent inquiry into the neo-Nazis in California, an FBI spokesperson said the bureau does not confirm or deny the existence of specific investigations. “We cannot initiate an investigation based solely on an individual’s race, ethnicity, natural origin, religion, or the exercise of First Amendment rights,” the FBI said in a statement. “The FBI does not and will not police ideology.”

The bureau “investigates activity which may constitute a federal crime or pose a threat to national security”, the statement added.

The Bamn case follows numerous recent controversies surrounding the FBI’s targeting of leftist groups, including a terrorism investigation into Standing Rock activists, surveillance of black activists, and spying on peaceful climate change protesters.

The justice department inspector general previously criticized the FBI for using non-violent civil disobedience and speculation of future crimes to justify terrorism investigations against domestic advocacy groups, German noted, adding that the Bamn files suggest the FBI “seems to have learned nothing from these previous overreaches”.

Even knowing the FBI’s legacy of going after activists, the report was still shocking, said Shapiro.

“A bunch of anti-fascists showed up at a Nazi rally and were attacked by Nazis, and the response from the bureau was to launch a domestic terrorism investigation into the anti-fascists,” he said. “At its core, the FBI is, as it has always been, a political police force that primarily targets the left.”