In early June German authorities reopened legal proceedings against Becker after the federal prosecutor's office revealed that it could not rule out the possibility of a female suspect linked to three clues - on a motorcycle helmet, motorcycle gloves, and a jacket left in the getaway vehicle. But federal prosecutor spokesman Frank Wallenta announced on Tuesday in Karlsruhe that Becker was no longer a suspect due to the DNA evidence.
Siegfried Buback, a strong opponent of the leftist terrorist group during his term, was killed along with his driver Wolfgang Göbel, and a judicial officer, Georg Wurster, on the way to the court house in Karlsruhe in 1977. A motorcycle pulled up to Buback's Mercedes at a stoplight, and a passenger on the back opened fire with an automatic weapon.
But Becker has been "ruled out" from the investigation after the negative findings from the forensic institute at the Federal Office of Criminal Investigation (BKA), Wallenta said.
RAF members Christian Klar, Knut Folkerts, Günter Sonnenberg, Brigitte Mohnhaupt have all been convicted collectively of the crime, 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.
The federal prosecutor's office has also been investigating Stefan Wisniewski, after ex-terrorist Peter-Jürgen Boock recently implicated him as the possible shooter.
The head of the investigation at the Federal Court of Justice has threatened Mohnhaupt, Folkerts and Klar - who are no longer incarcerated - with new jail time if they don't break their silence about the event. That decision is currently under review by the court.
Buback's murder was the first crime in a series of terrorist acts by the militant communist RAF group in their radical opposition to the West German government that came to be known as "German Autumn" in 1977.