A German court on Wednesday issued a life sentence to a woman who impersonated a doctor causing the death of several people she treated.

Judges at the district court in Kassel said the evidence shows that the 51-year-old woman, whose name was not mentioned in accordance with German privacy rules, used a forged license to obtain a job as an anesthesiologist.

The German Press Agency (dpa) reported that the judges issued the ruling after the charges against her were proven and the death of three patients due to treatment errors, while others suffered serious harm. They sentenced the woman on three counts of murder and 10 counts of attempted murder.

The judges pointed to the particular severity of the crimes, which increased the difficulty of releasing the woman from prison after 15 years.

This is the amount of time that must be considered for the potential release of people sentenced to life imprisonment in Germany.

Prosecutors accused the woman of administering incorrect doses of drugs and failing to treat sepsis at a hospital in Fritzlar, a town near Kassel.

She was also said to be responsible for hours of oxygen deprivation as well as damage to the cardiovascular system and organ failure in patients, according to the German Press Agency (dpa).

After working at Fritzlar hospital from 2015 to 2018, the woman moved to a clinic in northern Germany. Officials from a regional medical association noted discrepancies in her records, and she eventually turned herself in on charges of professional fraud as reported by the Hess Medical Association and her former employer.