In the handbag of Anneliese Herschel, a twenty-one-year-old office worker from Werther who was found dead at the end of February 1968, police found a matchbox printed with the name of the Pferdediele, a tavern in Bielefeld. Witnesses there had seen her on the evening of February 27 with two men, and police learned that shortly before midnight she had taken the train to Herford. One of the two men had an alibi. The other was Ernst-Dieter Beck, twenty-seven, a laborer from Diebrock, and on March 1 officers arrested him at the Alte Börse, a bar in Herford. He said he had parted from her at two in the morning and spent the rest of the night reading a newspaper in the waiting room of Herford station, but she had been killed at least two hours after two o'clock, and in his coat pocket they found her things, among them her lipstick. The post-mortem found that the strangling had gone on for minutes. He admitted the killing, and a newspaper report of March 4 quoted him as saying he had done it to satisfy his lust.
A fingerprint from an apartment in Herford where a woman had been strangled three years earlier then matched his. Ursula Fritz, twenty-nine, also an office worker, had met him at a dance hall on May 25, 1965, and asked him to dance. After several evenings out she invited him to her mother's apartment in Herford, where she was living alone, and he strangled her there and left unseen. Because she had planned a trip to the Netherlands nobody thought her missing, and neighbors found her ten days later. Beck had been one of four men suspected at the time, with no firm evidence against any of them.
The inquiry reached back further still, to April 8, 1961, when Ingrid Kanike, twenty-three, an office worker, disappeared on her way home from a Polterabend, the party held on the eve of a wedding, and was found strangled in a mill near Rehme. That investigation had been enormous by the standards of the place and time. All eighty-four guests at the party were questioned closely and more than a thousand leads were followed. Several men were suspected, among them Kanike's own father, who never freed himself of the accusation because he died before Beck was arrested.
Beck had been born at Gohfeld on October 2, 1940, and before the first killing had already been convicted several times, of theft, fraud, forgery, assault and sexual assault. After his arrest he was sent to the state hospital at Marsberg for a psychiatric report, and there, unexpectedly and quite quickly, he confessed all three murders to the head of the institution. His lawyer, Schlüter, moved for a cytogenetic report from the Institute of Human Genetics at the University of Marburg, which made Beck the first person accused of murder in German legal history on whom a chromosome test was carried out.
On November 4, 1968, in a packed courtroom, the assize court of the Bielefeld regional court, three professional judges and six lay jurors, convicted him of all three murders and sentenced him to three terms of life imprisonment with loss of his civil rights for life. He was still serving that sentence half a century later, and died at the prison hospital in Fröndenberg on April 29, 2018, at seventy-seven.