The 40-year-old doctor is accused of having killed twelve women and three men between September 2021 and July 2024, when he worked as a doctor in Berlin.
The investigators fear that the doctor, who is a specialist in palliative medicine, may be behind even more deaths.
According to the suspicions, he has injected the victims with lethal doses of drugs. In five of the cases, he is also accused of having set fire to their homes to conceal his crimes.
He was arrested in August last year after a colleague had raised suspicions when several of the doctor's patients had died in fires. Initially, he was suspected of four deaths, but during the investigation, the number has grown to 15.
A further 96 cases are being investigated, says a spokesperson for the prosecutors to AFP, including the death of the doctor's own mother-in-law.
The doctor has not commented on the allegations. The prosecutors are seeking a life sentence.
