A German doctor has been charged with giving eight of her cancer patients lethal overdoses of morphine but insists she was performing mercy killings at their request, prosecutors said Thursday. The 55-year-old physician whose name was not released by authorities was charged with eight counts of second-degree murder after a more than two-year investigation. Public prosecutors in the northern city of Hanover said her patients in a hospital in the nearby town of Langenhangen had not expressed the wish to die. The Hanover regional court must now decide whether she will stand trial. She could face up to 15 years in prison in convicted. The investigation began in September 2003 when a public health insurance company pressed charges against the doctor. She was held several weeks for questioning in 2004, prompting public protests from some of her other patients. The doctor lost her medical license in the wake of the probe and closed her private practice, which she ran alongside her work in the clinic.