Tucked into last week’s indictment of Roger Stone, the brash longtime confidante of President Donald Trump, was a fleeting reference to an attorney who had the ability to contact WikiLeaks founder Julian Assange.

Prosecutors wrote that an email from Stone, seeking dirt on Democratic presidential candidate Hillary Clinton, was forwarded to the attorney, who wasn’t identified — adding an intriguing character to the mystery over possible links between Trump’s presidential campaign and WikiLeaks.

That attorney is Margaret Ratner Kunstler, according to a person familiar with the investigation. Kunstler, 73, who lives in Brooklyn, is a civil rights lawyer and activist who was married to two prominent, late civil rights attorneys, William Kunstler and Michael Ratner. She has been involved in high-profile cases for nearly a half century, from the revolt at Attica prison and the protest known as Occupy Wall Street to the defense of hacker Jeremy Hammond, who was linked to the group known as “Anonymous.”

More recently, she assisted in representing WikiLeaks. In 2015 and 2016, she helped Assange, who is holed up in the Ecuadorian Embassy in London amid fears of arrest, plan his legal strategy and arrange media appearances. Her name popped up in public when President Trump’s son, Donald Trump Jr., released messages after his correspondence with WikiLeaks became public. One of these, a 2017 direct message from Assange’s Twitter account to Donald Jr., identified Kunstler as a person for the Trump administration to contact at WikiLeaks.

The Stone indictment provides the first suggestion by special counsel Robert Mueller’s office that Kunstler may have been asked to act as an intermediary with WikiLeaks during the crucial pre-election months of 2016. It appears to throw a left-leaning champion of civil disobedience and free speech into a mix of right-wing allies of Trump whose methods are now under deep scrutiny. It also provides another clue that Mueller’s team is focusing on the role of Assange, whose WikiLeaks published troves of Democratic National Committee emails that the special counsel says were stolen by Russian state hackers.

The indictment doesn’t say whether the attorney in fact made the connection between Stone and Assange.

Kunstler requested a detailed list of questions from Bloomberg News when asked last week to comment on questions including about her work as Assange’s adviser and any emissary role she may have wittingly or unwittingly played. She hasn’t answered the queries.

Stone, 66, pleaded not guilty Tuesday to charges that he obstructed a congressional inquiry, lied to lawmakers about his communications involving WikiLeaks and the Trump campaign, and tampered with a witness. The indictment details his alleged efforts to find an intermediary to contact WikiLeaks. The evidence includes a series of conversations and text messages with a radio host referred to as “Person 2,” whose description matches Randy Credico, a New York radio host and a longtime friend of Kunstler’s.

Credico had hosted Assange on his radio show in August 2016, an appearance that Kunstler helped arrange, Credico told Bloomberg News last fall. A few days after the show aired, the radio host sent Stone a text message claiming Assange “has kryptonite on Hillary Clinton,” according to the indictment.

By mid-September, prosecutors said, Stone emailed the host a link to a news story critical of Clinton’s actions as secretary of state, asking he check with Assange for other hacked emails that could confirm the accusations. Two days later, according to the indictment, the radio host believed to be Credico forwarded the email to “a friend who was an attorney with the ability to contact” Assange. That was Kunstler, according to the person familiar with the matter.

On Oct. 1, the radio host sent Stone a text: “Big news Wednesday…now pretend u don’t know me…Hillary’s campaign will die this week,” according to the indictment. Several days later, WikiLeaks began releasing hacked emails, some of which were considered damaging to her election bid.

Kunstler’s name has come up before in connection with Trump’s inner circle. Among the electronic messages released by Donald Trump Jr. was an April 2017 direct message to him from Assange’s Twitter account, suggesting he provide WikiLeaks with copies of any emails about the infamous June 2016 Trump Tower meeting with a Russian lawyer, who purportedly had dirt on Clinton. The idea, according to the exchange, would be to blunt the impact of news stories about the meeting. That message named Kunstler as a contact person.

Trump Jr. has claimed he never responded to the request. In testimony before the Senate Judiciary Committee in November 2017, he said he never corresponded directly with Assange and that all of his correspondence with WikiLeaks went through “a lady that appeared to work at a law firm.”

Trump Jr.’s lawyer, Alan Futerfas, didn’t respond to emails asking whether his client ever corresponded with Kunstler or whether the ‘lady that appeared to work at a law firm’ was Kunstler. Contacted after Stone’s indictment, Credico declined to comment.

Kunstler was also asked in November 2017 to testify before the Senate Judiciary Committee and to provide any documents referring to hacked emails as well as communications between herself and Trump campaign representatives. Her lawyer declined, citing attorney-client privilege, according to a person involved with the committee’s inquiry.

While Kunstler hasn’t publicly addressed the leak of DNC emails, a Twitter feed bearing her name has mixed civil-rights retweets with links to stories disparaging Mueller’s investigation. On October 13, 2016, six days after WikiLeaks began releasing the emails, the account retweeted a Guardian column headlined “If Trump leaks are OK and Clinton leaks aren’t, there’s a problem.”

The daughter of left-wing parents who met at a Mayday parade, Kunstler graduated from Sarah Lawrence College and began at Columbia Law School in 1967. There, she helped defend students who took over the campus the following year.

After law school, she worked worked as a legal-aid lawyer before going into private practice with Michael Ratner, whom she married. But a trip to St. Croix in 1973 upended her marriage and changed the course of her legal career. She went to assist Kunstler in defending the Fountain Valley 5, a group of black men charged with murdering white tourists at a golf resort owned by the Rockefellers.

The defendants were all convicted, but “at the end of this experience, Margie and Bill were in love,” Michael Ratner said in a speech in his ex-wife’s honor in 2008. She and Kunstler were married until his death in 1995.

She still occasionally collaborated with Ratner, who was president of the Center for Constitutional Rights, co-authoring in 2011 “Hell No: Your Right to Dissent in 21st Century America.” They both also represented WikiLeaks and its supporters until his death until May 2016.

The complete scope of her work for WikiLeaks is unclear. In 2015, she and Ratner wrote a letter to Eric Schmidt, then chairman of Google, complaining that the company waited more than two years to inform WikiLeaks that the company had turned over some of its members’ emails and other data. A Google spokesman said at the time that its policy was to inform people about government requests for their data except in limited cases such as a court gag order “which sadly happens quite often.”

A few months after Trump’s election, Kunstler publicly criticized Laura Poitras, the film maker who directed the Edward Snowden documentary “Citizen Four,” saying that Poitras’s subsequent film about WikiLeaks placed the organizations’ members at risk.

As Kunstler’s name has intermittently surfaced in connection with WikiLeaks, it has caused consternation in the left-wing legal community. Her long-time friends and associates find it unthinkable that an activist and stalwart in the civil rights bar might have aided the Trump campaign or administration, even inadvertently.

“She hates Donald Trump. We all hate Trump,” said Deborah Hrbek, a lawyer who worked with her and has known her for decades.