A German nurse has admitted to murdering 100 patients between the ages of 34 and 96, at two hospitals in Northern Germany between 2000 and 2005.
Niels Hoegels, 41 confessed to killing his patients over a 5-year period between 2000 and 2005.
Hoegel is accused of giving his victims various non-prescribed drugs, in an attempt to show off his resuscitation skills to colleagues and fight off boredom.
Hoegel confessed to the crimes on the first day of his trial in a court in Oldenburg, Northwest Germany. Saying they were all correct.
Around 126 relatives of the victims are co-plaintiffs in the trial, which is expected to run until May next year, a court spokeswoman revealed.
Hoegel is already serving a life sentence for six convictions, including homicide and attempted homicide.
It was those convictions that prompted authorities to comb through the records and exhume bodies of former patients in the clinics where he worked.
Earlier this year he was charged with another 97 murders.
Prosecutors said Hoegel should have been aware that the drugs he gave to patients at hospitals in Delmenhorst and Oldenburg could cause life-threatening cardiac problems.
In past hearings, Hoegel said he felt euphoric when he managed to bring a patient back to life and devastated when he failed.
Police said the final number of murders may never be known because some possible victims were cremated.