Stephan Letter was born on September 17, 1978, in Herdecke in North Rhine-Westphalia. He did his civilian service as an ambulance paramedic with the German Red Cross at Ludwigsburg from 1998 to 1999, trained as a nurse at the Ludwigsburg clinic, and took up a post on a ward at the hospital in Sonthofen, in the Allgau in southern Bavaria, on January 6, 2003.
He began killing patients within weeks. The method was two-stage: he sedated the patient first, then injected a muscle relaxant, either Lysthenon or Esmeron, in a lethal dose. Those drugs cause respiratory paralysis and are difficult to detect in blood afterwards, which is the reason the deaths passed as natural for so long. The patients were mostly old and gravely ill, aged between forty and ninety-five.
Across roughly eighteen months on the ward there were more than eighty deaths during his shifts.
He was not caught for the killings. On July 29, 2004, he was arrested for stealing medication, and unsealed drug vials were found at his flat. It was in the course of that investigation that the number of deaths on his shifts came into focus.
The evidential problem was the bodies. Prosecutors at Kempten exhumed more than forty patients, but another thirty-eight had already been cremated, and in those cases nothing could be recovered. Whatever the true total, it was fixed at that point by what remained to be examined.
He was charged on September 15, 2005, and the trial opened at the Kempten regional court on February 7, 2006. At the start of it he admitted giving patients a lethal mixture of drugs taken from hospital stock, but denied that he had acted with malice, saying he had wanted to release them from suffering and that he had not been able to cope with the work.
On November 20, 2006, the court convicted him on twenty-eight counts: twelve of murder, fifteen of manslaughter, and one of killing on request. He was acquitted of one count of dangerous bodily harm and fined on five counts of theft. Two of his patients survived. He was sentenced to life imprisonment with a finding of particular gravity of guilt, which removes the ordinary prospect of release after fifteen years, and banned from the nursing profession for life.
The court found that he had killed patients whose case histories he barely knew and some who were recovering, which is what defeated the account he had given of himself.
The figures differ between sources by one. Twenty-eight counts were proved. Twenty-nine is cited where a further case is counted that was not separately established in the verdict.
He is serving the sentence at Straubing. At the time it was the largest case of serial killing in post-war Germany, and it held that position until the scale of Niels Hogel's killings became known. In Bavaria it produced a public argument about what controls exist on wards where deaths are expected.