German killer nurse murdered 'at least 90 patients': police

Berlin : A male nurse jailed for life two years ago for killing two hospital patients with lethal drug overdoses murdered at least 90 patients in total, and possibly twice as many, police said Monday, calling it post-war Germany's worst killing spree.

Niels Hoegel, 40, was jailed in February 2015 for two murders and four counts of attempted murder or causing bodily harm on intensive-care patients at the Delmenhorst hospital near the northern city of Bremen.

Police said Monday that forensics experts had since exhumed and analysed more than 130 additional bodies and had found evidence of a vastly higher death toll at two hospitals where Hoegel had worked between 1999 and 2005.

"The insights we were able to gain are terrifying, they surpass what we could have imagined," said Johann Kuehme, police chief in the city of Oldenburg, where the other hospital is located.

The death toll "is unique in the history of the German republic," said the chief police investigator in the case, Arne Schmidt, adding that Hoegel killed "without a discernable pattern" and preyed especially on those in critical condition. 

There was "evidence for at least 90 murders, and at least as many (suspected) cases again that can no longer be proven," he told a press conference, declaring himself "speechless" at the outcome.

Hoegel has admitted to injecting patients with drugs that can cause heart failure or circulatory collapse so he could then try to revive them and, when successful, shine as a saviour before his medical peers.

He earlier testified that at times he acted out of "boredom", that he felt euphoric when he managed to bring a patient back to life, and devastated when he failed.