A “homicidal” doctor convicted of the deaths of 15 patients in Germany has been sentenced to life in prison.

German palliative care physician accused of killing 15 patients who was described by prosecutors as having a “lust to kill” was convicted on Wednesday and sentenced to life in prison.

This Berlin doctor, 41, identified as Johannes M., is suspected of having killed 12 women and three men between September 2021 and July 2024 using sleeping pills.

On at least five occasions, he is said to have set fire to the victims' houses to cover up the killings.

The authorities said during the trial that they are still investigating a number of other people who may have been killed by Johannes M.

The doctor allegedly “administered anesthetic and muscle relaxants to his patients without their knowledge or consent,” the Berlin prosecutor's office said in a statement. “This paralyzed the respiratory muscles, leading to respiratory arrest and death within minutes.”

Prosecutors had previously sought a life sentence, additional measures to prevent parole and a lifetime ban from practicing the drug.

On Monday, Johannes M. admitted that he “killed people” and told the court that “I'm giving up hope.”

He said he now understood the “enormity of the suffering” he had caused, the Frankfurter Allgemeine Zeitung daily reported.

Prosecutors and police previously said the suspect had no motive other than to kill, and that the suspect's actions fit the legal definition of “desire to kill.”

The victims, all of whom were receiving help at the time, are between 25 and 94 years old.

“Why do people kill?”

In another incident, the suspect is accused of killing two patients in one day.

On the morning of July 8, 2024, he is accused of killing a 75-year-old man in his home in the central Berlin district of Kreuzberg.

After a few hours, it is said that he attacked again, and a 76-year-old woman died in the neighboring district of Neukoelln.

The suspect's attempts to set fire to the crime scene failed when the fire did not take hold, prosecutors said.

Suspicions about Johannes M.'s activities were first raised by those in care, which led to a police investigation. He was remanded in custody until August 2024.

Investigators are looking into four cases, but the number of suspects continues to grow, as more cases are being investigated.

“The suspect seems to have had no reason to kill people other than suicide,” prosecutors said last year.

According to German media, Johannes M. wrote his doctoral thesis on murder and began the paper with the words, “Why do people kill?”

The case remembers that of German nurse Niels Hoegel, who was sentenced to life in prison in 2019 for killing 85 patients. Hoegel, believed to be Germany's most prolific serial killer, executed patients at the hospital by lethal injection between 2000 and 2005, before he was caught red-handed.

In another case, a nurse was sentenced to life in prison in November for killing 10 patients and attempting to kill 27 others by lethal injection.

Last year, German police revealed that they were investigating another doctor who allegedly killed many patients, especially the elderly.