Little time? At the end of the text there is a summary.

Stephan K. is fighting with tears. The 48-year-old was a colleague of Niels Högel, once also a good friend. As a nurse, they worked together first in the Klinikum Oldenburg, then in Delmenhorst. 15 years later, Stephan K. can barely speak of the fact that the man he considered a friend killed a number of patients.

"The dimension is not tangible," says Stephan K. on Friday in the district court Oldenburg. "It's very hard to handle." As a nurse, you want to tell the families of patients, "You're putting your family in our hands, your trust is not a mistake, we're on the right side."

Stephan K. can not say that anymore. Because he himself has lost this trust. "I can not imagine ever practicing the profession again," he says. "The trust that is necessary to work in a team I can not get anymore, I never want to face this situation again, the trust has been destroyed to the maximum."

The fact that Niels Högel was finally arrested in the summer of 2005 is also thanks to Stephan K. The witness had already reported this on a previous day of the hearing. But three years earlier, in 2002, the series of murders could have been stopped.

Suddenly Niels Högel stood in the office of the works councilor

This was also recognized by Pia U. when she heard of Högle's arrest in 2005. Pia U. was a member of the works council at Klinikum Oldenburg. In August 2002, Högel suddenly stood in her office. He was completely dissolved, reported the 59-year-old on Thursday in court. He told her that the hospital management had summoned him to him. Now he was afraid for his job.

After frequent emergencies in Högel's services, the management, senior doctors and nurses were reluctant to let him leave the patients' beds in Oldenburg. They apparently did not care about the lives of patients in other clinics. Högel was urged to leave the Oldenburg clinic. From one day to the other he was on leave, got two and a half months full salary and a good report. The clinic in Delmenhorst hired him innocently in December 2002. Högel continued to murder.

Until a nurse acted in Delmenhorst in the summer of 2005. She caught Hoegel in the act, took a blood sample from the patient, called Stephan K. for help. There was a heart medication in the blood that had no business there. Högel was arrested. And Pia U. in Oldenburg began to feel guilty.

She has a guilty conscience, blames herself for not pursuing the case in 2005, entrusting her to the head of anesthesia in 2005, who had called for Högel's dismissal in 2002. Pia U. made a note of this conversation. He finds himself in the files of the Oldenburg Works Council. There was no reason to feel guilty, after all, there had been no concrete suspicion of Högel in Oldenburg, the doctor replied. Also noted that Pia U. With the addition that she remembered otherwise.

"Whether he would be seen as a fireman who lays the fire himself"

In fact, everything is in the files of the works council. The presiding judge Sebastian Bührmann reads excerpts. There is, for example, the note on a telephone conversation between Pia U. and Högel in September 2002. Högel said that he had approached the chief anesthetist and wanted to know what exactly he was accusing him of.

Högel told the works council employee that he had asked the doctor "if he was seen as a firefighter, who puts the fire himself and then would be there". This is what Pia U. wrote it down. The doctor did not respond. Today Högel's sentence reads like a confession in question form. The nurse had probably already murdered at least 36 patients at this time. He had injected them with drugs that had them collapsed and then tried unsuccessfully to revive them.

The next day after this call, there was the next call, this time without Högel. For the first time, the suspicion was voiced that Högel deliberately brought about the emergencies. A mistake he considers excluded, said the then managing director of the Oldenburg Clinic in 2002. Again, the works council wrote.

The tremendous suspicion that can be read there black on white, her documented guilty conscience - all that the witness Pia U. wants to remember only vaguely today. She does not have a conversation situation before her eyes, assures her as a witness in court.

Court does not dismiss witnesses the memory gaps

"You swear by God the Almighty to have told the truth and nothing but the truth?" Asks the judge. "I swear, God help me," says Pia U. But above all she conjures up memory gaps.

Against four witnesses is already running a case of perjury. The prosecution does not believe their alleged in court allegiance and investigated on suspicion of false statements under oath. The witnesses are not much help in clarifying the biggest murder series in the Federal Republic.

Remains the defendant himself. "It is never too late for the truth, Mr. Högel!" Judge Bührmann has already made several appeals, but this week he does it again. Högel nods. But you can not rely on him. Bührmann knows that only too well. It is the third trial against Högel before Bührmann's chamber. For years Högel had lied to the judges and asserted that they had first murdered in Delmenhorst and not already in Oldenburg. Only in 2014 he admitted to having already killed in Oldenburg.

100 actions are now in the current process. In the years 2000 to 2005 Högel is said to have murdered 36 patients in Oldenburg and 64 in Delmenhorst. But there is a gap that surrounds Richter Bührmann. From January to September 2002, there is no accused murder. But why should Högel have stopped in the middle? Bührmann does not believe that. "It's hard for me to imagine that you just kept quiet during that time," he says. Högel takes note silently

The court has commissioned the Berlin law psychologist Max Steller to provide an opinion on the credibility of the information provided by Högel. It is an extremely rare order. Legal psychologists usually judge the statements of alleged victims of a sexual offense. Judging whether a defendant lies or not is actually one of the classic tasks of judges, not psychologists. But in the Högel case, Richter Bührmann wants to play it safe this time. He does not want to experience a nasty surprise again.

In summary: Could Niels Högel's murder series have been stopped earlier? Notes from an Oldenburg works council document that there were grounds for suspicion back in 2002 - three years before Högle was arrested. In court, the woman relied on memory gaps. Thus their statement should hardly help the court in the taking of evidence - as well as the appearances of several other witnesses, they do not remember anything after own statement. However, the Chamber has doubts as to whether this is true: four witnesses are being tried for perjury.