The man who stabbed an American student to death in Rotterdam last December has been jailed for six years, to be followed by psychiatric prison.

Sarah Papenheim, a psychology student from Andover, Minnesota was studying at the Erasmus University when she was killed by Joel S, who lived downstairs in the same student complex.

S, who knew his victim, was arrested at Eindhoven railway station shortly after her body was found. During the trial he told judges he could not remember much about the killing. Papenheim was stabbed 27 times and cut with a knife a further 10 times.

He said he knew he was angry with her. ‘And then I saw the blood on the wall and she was lying on her back,’ he told the court during the trial. Experts said S had lost his grip on reality and suffered from autism, schizophrenia and a psychosis.

S was found guilty of manslaughter rather than murder because the court accepted he had not set out to kill her.

The girl’s mother and the US ambassador to the Netherlands Pete Hoekstra were in court to hear the verdict, broadcaster NOS said.

A week before the murder, Papenheim had told a friend she was worried about S and they contacted social workers who visited him twice but said there was nothing they could do.