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."