BERLIN — A former nurse serving a life sentence for murder went on trial Tuesday on charges that he killed another 100 patients at two hospitals in Germany.

The nurse, Niels Hoegel, 41, told a court in the northwestern city of Oldenburg that the charges against him were largely accurate, the news agency DPA reported.

The murder charges stem from Mr. Hoegel’s time at a hospital in Oldenburg between 1999 and 2002 and at a hospital in Delmenhorst from 2003 to 2005. The patients were ages 34 to 96.

Mr. Hoegel was convicted in 2015 of two murders and two attempted murders. During that trial, he said he intentionally brought about cardiac crises in some 90 patients in Delmenhorst because he enjoyed the feeling of being able to resuscitate them. He later told investigators that he also killed patients in Oldenburg.