Sergeant? An old town, very pretty. A girl was found murdered there on 1 July 1903. At first it was assumed it was suicide. There was a glass on the bedside table with prussic acid in it, or KCN, to be more precise, potassium cyanide.
âHow had the girl managed to obtain the poison? A mystery. Her parents found her dead in her bed one morning at eight and immediately called the police. At that time the superintendent of the Fribourg police was a man who had heard something of the latest methods of detection. On the glass â it was a straight-sided glass, such as people use to keep their toothbrush in â he noticed a clear fingerprint. So he wrapped the glass up in tissue paper and, since in those days there was only one man in Switzerland who knew anything about this new science of dactyloscopy, he rang me up.
âI happened to be fairly free â in July thereâs nothing much for an lawyer to do â so I went to Fribourg, taking my camera with me, some powdered cerussite and powdered graphite.
âI wonât bore you with details. I got a nice clean photo of the fingerprint, developed it, took the dead girlâs fingerprints, her parentsâ, the superintendentâs. And then I compared them. It was a tedious business, comparing all the fingerprints, but soon I was sure that some other person had been in the girlâs room and put the glass with the potassium cyanide on her bedside table. And that person had murdered her.â
Herr Rosenzweig, who, despite his name, did not look at all Jewish, got a piece of cotton wool and put it in his ear.
âMy teeth,â he said apologetically. âThey ache. What can one do, Sergeant? Itâs old age.â
He didnât use the Bernese dialect but the standard Swiss German all educated people spoke by then . . .
âYes, someone from outside had put the glass with potassium cyanide on the girlâs bedside table. When the autopsy revealed that she was pregnant, it seemed clear the girl had been murdered â and by a very cunning killer, since the only clue he had left was a thumbprint on the glass.
âYou must remember, Sergeant, in those days criminals were not as well informed as they are today; they didnât know that a fingerprint could give them away. They didnât go about their business in surgeonâs gloves. And it was chance, pure chance that the superintendent in Fribourg thought of me and rang up. Chance, too, that I had time . . .
âThatâs how I came to have this photograph. Iâve looked at it a lot â I enlarged it, but the enlargements werenât a success. I compare it with every new fingerprint I get for my collection, in the hope Iâll eventually find the man with that thumbprint.
âTo complete the story I was telling you, the 1903 investigation got nowhere and fizzled out. The girl was allowed a lot of freedom, by the standards of the time. She came to Bern twice a week â she had piano lessons here â and sometimes she stayed overnight. With a girlfriend, she said.
âThe superintendent in Fribourg contacted the Bern police and they established that the girl had stayed in the Hotel zum Wilden Mann several times, each time accompanied by a young man. But the young mancould not be found. The police, as the saying goes, were baffled. The hotel porter did give a description of him, but it was so sketchy it was no use.
âA student? Someone studying in Bern? Chemistry? Medicine?
âThat left the mystery as to why he had travelled to Fribourg. He could just as well have given the girl the potassium cyanide tablet and told her it was very good for headaches. But no, heâd gone to Fribourg, got into the girlâs room, dissolved the poison in water and got her to drink it. It wasnât too difficult. Ulrike â the girl was called Ulrike Neumann â had an attic room and the front door stayed open until ten oâclock. There were three