In order to show off his skills in bringing patients back from the brink of death, Niels Hoegel repeatedly injected people under his care with lethal medication. His colleagues mostly claim ignorance about his actions.
A German nurse believed to be the most prolific serial killer in the country's post-war history was handed a life sentence on Thursday for murdering 85 patients in his care.
Judge Sebastian Buehrmann called Niels Hoegel's killing spree "incomprehensible" and acknowledged the trial left many families with painful unanswered questions.
The 42-year-old murdered patients selected at random with lethal injections between 2000 and 2005, when he was caught in the act.
Hoegel has already spent a decade in prison following a previous life sentence he received for six other murders.
The exhumation and autopsy of more than 130 bodies were necessary to build the case for the prosecution.
Police suspect that Hoegel's final death toll may be more than 200.
But the court was unable to say for sure because of gaps in Hoegel's memory and because many likely victims were cremated before autopsies could be performed.
Buehrmann of the regional court in the northern city of Oldenburg said the number of deaths at Hoegel's hands "surpasses human imagination".
He expressed regret that the court had not been "fully able to lift the fog" for loved ones about other likely victims.
On the final day of hearings on Wednesday, Hoegel asked his victims' families for forgiveness for his "horrible acts".
"I would like to sincerely apologise for everything I did to you over the course of years," he said.
Unchecked for years
Caught in 2005 while injecting an unprescribed medication into a patient in Delmenhorst, Hoegel was sentenced in 2008 to seven years in prison for attempted murder.
A second trial followed in 2014-2015 under pressure from alleged victims' families.
He was found guilty of murder and attempted murder of five other victims and given the maximum sentence of life.
At the start of the third trial in October, Buehrmann said its main aim was to establish the full scope of the killing that was allowed to go unchecked for years.
"It is like a house with dark rooms – we want to bring light into the darkness," he said.
Victims' advocates say the court has failed woefully at the task, due in large part to Hoegel's own contradictory testimony.
After admitting on the first day of testimony to killing 100 patients in his care, he later revised his statement.
He now says he committed 43 murders but denies five others.
For the remaining 52 cases examined by the court, he says he cannot remember whether he "manipulated" his victims – his term for administering the ultimately deadly injections.
"That leaves people in the dark – it doesn't allow them to mourn," Petra Klein of the Weisser Ring crime victims' organisation in Oldenburg said.
She described the legal proceedings as "trying" for the loved ones.
Psychiatrist Max Steller told the court that while Hoegel bears responsibility for his acts, he suffers from a "severe narcissistic disorder".
He "is always fundamentally ready to lie if that allows him to put himself in a better light", Steller said.
The defendant claims, for example, not to remember his first victim, who died on February 7, 2000.
However, a serial killer never forgets his first victim, Steller asserted, "meaning that he probably 'manipulated' before that".
Bringing patients back from dead
Driven by a desire to show off his skills in bringing patients back from the brink of death, Hoegel repeatedly gambled with the lives of vulnerable victims.
Most often, he lost.
While former colleagues in Delmenhorst admitted to having had their suspicions about Hoegel, all the staff from Oldenburg who testified said they were oblivious to the body count stacking up on his watch.
Buehrmann appeared exasperated by what he called "collective amnesia".
Ten of the witnesses are now facing possible charges for perjury, according to a spokesman for the prosecution.
Klein said that, at this point, the biggest hope of the victims' families was that Hoegel "should never emerge from prison".
She said the idea that he would one day walk free –– which is not inconceivable under the German justice system –– would be "unbearable for many of them".