The neo-Nazi Sebastian T. seems to be certain: the law cannot harm him.

When the judge interrupted the hearing in the hall of the Berlin-Tiergarten district court for a few minutes on Monday of this week, the defendant stepped out of the hall, both hands raised in a gesture of victory.

He is accused of having sprayed the portrait of Hitler supporter Rudolf Hess and SS runes on walls and house walls in the south of the city together with his comrade Tilo P.

If it were up to the state security investigators, T. and P. would have to stand trial not just for a few Nazi graffiti, but for completely different offenses: for their alleged involvement in the longest series of right-wing extremist attacks since the NSU murders.

There is a tremendous suspicion: prosecutors who may delay investigations and secretly sympathize with right-wing extremists.

Police officers who allegedly sabotage surveillance and divulge official secrets.

And above all the question hovers: Are these investigative mishaps, or is there a system failure here, or even worse: a deliberate failure of the investigative authorities?

Is the alleged graffiti smearer T. in reality a key figure in a scandal that is reminiscent of right-wing extremist police networks in Hesse and the crimes of the NSU?

The setting: Berlin-Neukölln.

Here, in the less trendy south of the district in the old workers' settlements in Britz and Rudow, strangers have been carrying out arson attacks on left-wing local politicians, refugee workers and a bookseller for four years.

Light cars, throw stones into glass.

Spraying death threats on house walls.

The public prosecutor's office has so far led over 60 preliminary investigations to the "Neukölln crime complex" - largely unsuccessful.

There has been little real progress in four years.

Why is that?

It all started with a conflict between two rival youth groups, says an official who has long dealt with the series of attacks: the right-wing teenagers from Neukölln against the left, there were fights and even then there was arson.

But the youngsters became adults.

And at some point they had enough.

Only the then NPD man Sebastian T. and some of his comrades not.

T. is always on trial.

And finally, according to the judiciary, he has to go to prison for a year for attempted dangerous physical harm.

In the calendar of the Berlin authorities, the series of attacks begins when T. is released from prison in May 2016.

The police counted four arson attacks in the same year, and a right-wing extremist motive is suspected behind all of them.

Because it always hits anti-fascists in South Neukölln, the SPD politician Mirjam Blumenthal in the Hufeisen-Siedlung, for example, and the bookseller Heinz Ostermann, who campaigns against the AfD.

A grill lighter on the front tire and after a short time the engine block is on fire.

Even at this time, the investigators suspected T., now 34 years old, and his comrades.

Also Tilo P., a right-wing extremist with contacts to the Hertha BSC hooligans and at the time a member of the AfD Neukölln.

But the investigators don't catch anyone.

Until the evening of January 15, 2018. The left-wing politician Ferat Kocak meets with party friends in a pub.

As he is on his way home, P. and T. talk to each other on the phone.

P. points out a red Smart to T., T. tells him to follow suit.

The statements come from a monitoring log.

The officers of the constitution protection, who overhear it, realize: The two Nazis are spying on a new target.

An investigation success, finally.

If the officers are clever now, they could prevent the next attack.

Or even provide evidence for a case against T. and P.

But it doesn't come to that.

The person responsible for the protection of the constitution calls the LKA and passes on the find.

A few days later the intelligence was sent in writing to the police, with the request not to speak to either the neo-Nazis or possible victims of the attack in order not to endanger the surveillance.

Instead, the police create a list of all the owners of Smarts in Neukölln.

Because at this point in time they do not yet know for sure who exactly the Nazis are targeting.

The list ends with three names, including Kocaks.

He is an immigrant child.

Refugee workers.

A perfect destination for P. and T.

The officers could now warn Kocak, park a police car in front of his house and protect him.

But nothing like that happens.

On the night of February 1st, Kocak's car burns.

The flames hit the wall of the house in which he lives with his parents, dangerously close to a gas pipe.

Shortly afterwards, the LKA receives another letter from the Office for the Protection of the Constitution.

It summarizes everything that the authorities have known for two weeks, with the note that it "suggests that the current arson attacks are part of the crime series in Neukölln".

The police officers are mad at their colleagues from the Office for the Protection of the Constitution.

The investigators also realized at this time that they had already seen T. a year earlier, how he drives to Kocak's house, gets out there and looks at the doorbell. At that time, T. had regularly scouted out addresses. Apparently so regularly that the investigators simply missed the episode on Kocak's front door. Until his car was on fire.