The now 57-year-old is thought to have made a “crucial contribution in the preparation and execution of the attack,” according to prosecutors in Berlin. The authorities said last week that new DNA evidence had implicated Becker in the politically motivated killing on April 7, 1977.

Her genetic material was found on several envelopes of letters claiming responsibility for the murder of Buback, who was a strong opponent of the RAF. The leftist terror group killed him along with his driver Wolfgang Göbel and a judicial officer, Georg Wurster, on the way to the court house in Karlsruhe. A motorcycle pulled up to Buback’s Mercedes at a stoplight, and a passenger on the back opened fire with an automatic weapon.

Her arrest comes as a surprising turn in the ongoing investigation into one of the highest-profile killings carried out by the RAF. Only last year, investigators said testing on a motorcycle glove, helmet and jacket found after Buback’s death had ruled out any connection to Becker.

Becker was released from jail some 20 years ago after serving several years for RAF related crimes.

Former RAF members Christian Klar, Knut Folkerts, Günter Sonnenberg, Brigitte Mohnhaupt have all been convicted collectively of the Buback murder, but authorities remain unsure of who fired the deadly shots. Michael Buback, the son of the murdered prosecutor had repeatedly named Verena Becker as a possible suspect.