The lawyer defending Stephan E.*, the neo-Nazi on trial for the assassination of regional governor Walter Lübcke , has made his final statement to the court ahead of next week's verdict. In the hope of shortening his client's prison term, attorney Mustafa Kaplan argued that the defendant should be found guilty of manslaughter rather than murder.

Lübcke, a conservative politician in the state of Hesse who defended Chancellor Angela Merkel's refugee policies in the 2015 crisis, was shot dead on the porch of his home in June 2019. Stephan E. confessed to the killing, though he told the court that he had been helped by his erstwhile friend and co-defendant, Markus H., another known neo-Nazi, who has denied involvement.

For many observers, among them state prosecutor Dieter Killmer, Lübcke's killing could only be understood as the latest of a series of far-right terrorist attacks in Germany dating back to the Oktoberfest bombing in the 1980s.

But those attacks are not random. For the past 20 years, Germans have learned more and more about an underground network of neo-Nazis who are prepared to assassinate politicians, stockpile weapons, compile lists of the addresses of perceived enemies, and plant nail bombs in minority communities.

The most spectacular evidence of this came to light in 2011, when it emerged that three terrorists calling themselves the National Socialist Underground (NSU) had committed 10 murders and several bombings over the previous decade without ever being officially identified, let alone caught.

In the intervening years, a little light has been shed on some of the questions raised by the subsequent investigation: Who helped the NSU? What did Germany's domestic intelligence agency, known as the BfV, know? Why were the police apparently ignorant of the NSU's existence?

But the answers have consistently raised new questions. Most recently, new connections have emerged between the NSU and the case of the two men currently on trial in Frankfurt for Lübcke's murder.

Though there is no proof that they ever met the members of the NSU, it has become clear that they moved in the same circles, shared acquaintances in the regional neo-Nazi scene, and pursued similar criminal activities.

According to a new article by the German investigative outlet Correctiv, the defendant in the Lübcke case had about 60 contacts in the far-right scene, at least four of whom were investigated in connection with the NSU murders.

In a statement to DW, Hesse's state intelligence agency, reported that dozens of people who met both Markus H. and Stephan E. were currently being investigated, but the agency insisted there was no evidence that either of them met or helped the NSU.

There are plenty of circumstantial similarities between the Lübcke case and the NSU crimes. Like the NSU, Stephan E. compiled lists of enemies, potential targets. Some of the names appear on both lists. Like the NSU, Stephan E. carried out his alleged murder with a single point-blank gun-shot to the head. Like the NSU, Stephan E. built and detonated nail bombs. Like the NSU, the defendants in the Lübcke case, engaged in firearms training. The NSU had a large stash of arms and ammunition. Police also found a stockpile of illegally acquired weapons in Stephan E.'s possession, including five handguns, two rifles, 1,400 rounds of ammunition, and an automatic rifle.

'A helper network'

And yet there are other questions plaguing authorities: Could Lübcke's murder have been prevented? What did the intelligence agencies know about the two defendants, both of whom were prominent neo-Nazis with a history of violence? And could they have helped the NSU commit the one murder the group committed on its doorstep: That of 21-year-old Halit Yozgat in April 2006 in an internet cafe in Kassel (the city Lübcke later governed)? "We are still convinced there was a helper network in Kassel at the time, and that this murder was at least logistically supported," Hermann Schaus, a member of the Left party who served on the Hesse state parliament's committee to investigate the NSU, told DW.

The answer to all these questions may be in the files of the Hesse intelligence agency, which maintains informants in the neo-Nazi scene.

Schaus is now also on the committee investigating Lübcke's murder. For him, the associations are all too obvious — in fact, at one hearing for the NSU committee in 2016, he actually discussed the two neo-Nazis now accused of murdering Lübcke.

"My team and I noticed the names Stephan E. and Markus H. in the Verfassungsschutz documents at the time," he said. "We had already noticed that they were especially militant, but at the time the Verfassungschutz had assessed them as having 'cooled off' — in other words, they were no longer considered dangerous."

That remains an "explosive" question, Schaus said: "Why did we, as politicians — as amateurs, so to speak — turn out to be right, when the Verfassungsschutz was wrong?"

Schaus first learned about Stephan E. and Markus H. in 2016, three years before Lübcke's murder, from a 15-page intelligence dossier dated in 2009 that tracked neo-Nazis in Hesse.

"The description of Stephan E. and his readiness to commit violence — that was very noticeable," Schaus said. As the dossier showed, there was plenty to suggest that Stephan E. could turn out to be a terrorist: He put a pipe bomb in the cellar of a German-Turkish boy's home as a teenager, stabbed an imam in 1992, put another pipe bomb in a car outside a home for asylum applicants in 1993, and in 2009 was in of a crowd of neo-Nazis that attacked a leftist May 1 demonstration in Dortmund.

The mystery of the missing files

After he read that dossier, Schaus invited the officer who wrote it to testify to the committee as a

witness. "I remember asking the officer whether she thought Stephan E. should be considered a right-wing terrorist," Schaus said. "She couldn't confirm that."

But then something odd happened when Schaus asked her how she had prepared for the hearing: The officer told the committee that she had looked for the intelligence reports on the two men, and found that the files on Stephan E. and Markus H. were no longer in the system.

"So I asked: 'What do you mean no longer there? Have the files been deleted?'" Schaus said. "First she said, 'Yes.' Then: 'I don't know — in any case, they're no longer in the Verfassungsschutz system.'"

Much later, after the committee had ended its work, it emerged that the intelligence agency had deleted its files on Stephan E. and Markus H. in June 2016 — the same month that Schaus made his information request regarding the dossier that mentioned them. It's not clear whether the deletion happened before or after the request arrived. "It could be a coincidence," Schaus said. "But that's going to be one of the crucial questions on the committee." If it happened shortly afterward, it could indicate that someone in the intelligence agency was seeking to shield the two men.

As it happens, only the computer files were deleted (which is why the officer couldn't find them when she was preparing for her hearing), but a paper copy of the files was kept and stored away, because of a moratorium on shredding intelligence documents introduced in 2012 following the NSU scandal. "If it hadn't been for that scandal, all those files would've been lost forever," Schaus said. "We should have been given them earlier."

The only problem is: The state of Hesse opted to seal those files for 30 years. All that is known about them is that Stephan E. is mentioned multiple times.

*Editor's note: DW follows the German press code, which stresses the importance of protecting the privacy of suspects and victims and urges us to refrain from revealing full names.