They sentenced a nurse in Germany for 85 crimes: he liked smothering patients and trying to revive them.

An exterminate who liked to cause respiratory arrest in his patients because he felt he was able to resuscitate them, was sentenced on Thursday to 85 counts of murder for murder in a North West German court.

It is thought that he is the worst serial killer of modern German history.

The Oldenburg Court sentenced Niels Hoegel, 42, to life imprisonment and noted the "special gravity of the crimes" in his verdict.

Hoegel worked between 1999 and 2002 in a hospital in Oldenburg, in the north-west, and between 2003 and 2005 in another hospital in the nearby town of Delmenhorst. The murders took place between 2000 and 2005, according to the German press agency DPA. The Hoegel victims were between 34 and 96 years old.

Hoegel was convicted in 2015 of two murders and two attempted murder and was already serving a life sentence. The sentences are not cumulative in Germany, but the gravity of the verdicts almost guarantees that he will remain incarcerated beyond the standard penalty of 15 years.

In his first trial, the accused stated that he deliberately caused heart attacks in about 90 patients in Delmenhorst because he felt they could revive them. He then told the investigators that he had also killed patients in Oldenburg.

The authorities investigated hundreds of deaths and exhumed the bodies of former patients.

In total, Hoegel was charged with 100 murder crimes, although the court found him not guilty in 15 cases for lack of evidence.

During the seven-month trial, Hoegel admitted 43 deaths, denied five and said he could not remember the other 52.

In his final court plea on Wednesday, he was embarrbaded and regretted, saying that he was aware of the pain and suffering caused by his "terrible acts".

"To each and every one of you, I apologize for everything I did," he said.