On July 29, 2004, Stephan Letter, a twenty-five-year-old nurse at the clinic in Sonthofen, in the Allgäu, was arrested. Large quantities of drugs had gone missing from the hospital, among them the paralytic Lysthenon, and there were deaths no one could explain. Unsealed vials of medication were found in his apartment. When investigators looked at the eighteen months he had worked there, they counted more than eighty deaths on his shifts.
Letter was born in Herdecke, in North Rhine-Westphalia, on September 17, 1978. From August 1998 to July 1999, as his civilian service, he trained as an ambulance paramedic with the German Red Cross in Ludwigsburg, and afterward qualified as a nurse at the Ludwigsburg clinic. He started work at Sonthofen on January 6, 2003. The court later found that between February 2, 2003, and July 10, 2004, he killed twenty-nine patients there with poison injections, first a sedative and then a lethal dose of a muscle relaxant, Lysthenon or Esmeron, which stops the breathing.
Most of the patients were over seventy-five, though they ranged in age from forty to ninety-five. He also gave an unneeded injection to a twenty-two-year-old soldier who had been admitted with minor injuries from a fall; she lost consciousness and recovered. After confessing to ten of the deaths, he became the subject of a review of eighty-three cases. Investigators exhumed more than forty patients, but thirty-eight others had already been cremated.
On September 15, 2005, the prosecutors at Kempten charged him with sixteen murders, twelve manslaughters, one killing on request, one attempted manslaughter, two counts of dangerous bodily harm and theft. The trial opened at the Kempten regional court on February 7, 2006. He admitted some of the killings but said he had acted out of sympathy, to end the suffering of the sick. The prosecution showed that some of the dead had not been his assigned patients, and that some had been in stable condition and about to go home.
On November 20, 2006, the court convicted him of twelve murders, fifteen manslaughters and one killing on request, and sentenced him to life imprisonment with a finding of particular gravity of guilt, which bars the usual consideration for release after fifteen years. It also banned him from nursing for life. He was twenty-eight. The German press called him the death nurse of Sonthofen. He is serving his sentence at Straubing prison. His was described at the time as the largest series of killings in Germany since the Second World War, until the crimes of the nurse Niels Högel came to light.