BERLIN — A German nurse serving a life sentence for murdering two of his patients is believed to have killed at least 86 people entrusted to his care, officials said Monday, in what they described as an imagination-defying series of crimes. Johann Kuehme, the Oldenburg police chief, told journalists at a press conference Monday that the number of victims had left authorities “speechless.”

“The killings could have been prevented if the people responsible at the time — and I stress at the time — particularly at the Oldenburg clinic but also later on in Delmenhorst hadn’t hesitated to alert authorities, for example the state prosecution,” he said. Police said on Monday they now have evidence to charge him with the murder of another 84 patients — and they believe the actual number he killed could be even higher. In past hearings, the nurse, now aged 40, admitted deliberately injecting patients at two clinics in northern Germany with deadly drugs and then trying to revive them in order to play the hero, German media said. The nurse, identified as Niels Högel, was sentenced to life in prison in February 2015, after he confessed and a court in the northern town of Oldenburg found him guilty of administering overdoses of heart medication to some patients in an intensive care ward in Delmenhorst.
Investigations concerning Niels Högel, a German nurse already convicted for murdering two of his patients, revealed that the number of people killed while in his care is significantly higher, reaching at least 84, with some estimates being even higher. This makes Högel the serial killer with the highest known victim count in modern German history.