The fatal knife attack on a regional train in Schleswig-Holstein is reminiscent of similar bloody crimes in recent years. In some of these cases mental illness played a role, in others an Islamist ideology - or both together. Sometimes the motive remained diffuse.

The perpetrators are often people who came to Germany as asylum seekers without really getting a foothold in their new environment. It is people on the fringes of society who are not reached with the standard integration offers that are suitable for other people seeking protection, who are conspicuous for their violence and who often live in public institutions even after years.

The victims are passengers, apparently randomly selected passers-by. These are people whose life stories and names are usually unknown to the perpetrator, who is usually male.

Several cases over the past few years

Not only the stateless Palestinian who killed two young people he obviously did not know and injured five other passengers on a train on Wednesday is such a case. He was in prison for several crimes. In 2021 he was banned from living in a communal accommodation in Kiel.

The young, mentally ill Somali, who stabbed three women in Würzburg in the summer of 2021 - about six years after his arrival in Germany - had already become violent before and most recently lived in a homeless shelter. Like the radical Islamist who attacked a gay couple in Dresden in October 2020 and killed one of the two men, the attacker from the regional train was only released from custody shortly before the crime.

Disappointed hopes?

If you look at the biographies of the perpetrators, it is noticeable that many of them come from war or conflict regions, are rather young and childless, were not gainfully employed at the time of the crime and do not live with a partner or relatives. So far, however, there has hardly been any well-founded research on this group of perpetrators - with the exception of crimes motivated by Islamism. For example, on the question of what hopes and ideas the affected people came with - and how they later look at German society and the opportunities that it offers them or does not offer them. The nationwide picture of crime in the context of immigration does not help much here either.

Loneliness or isolation is always a factor, says criminologist Rafael Behr. Both can increase criminal energy, which is based on the socialization of the perpetrator, as well as psychological problems. In addition, the risk of mental illnesses going undetected is higher for people who are not part of a family environment or a circle of friends.

"Integration never works 100%"

It is possible that after the so-called wave of refugees in 2015, the opportunity was missed to mobilize sufficient resources for integration measures instead of spending the money on more police. At the same time, it must be clear to everyone: "Integration never works 100 percent," says Behr. "There will always be a few marginalized."

The mayor of Tübingen, Boris Palmer, commented on the attack on the train on his Facebook page with the words: "Anyone who becomes a danger to a country that provides help against danger must not stay." However, in practice this is often not possible. There are countries like Syria, to which no one has been deported for years. The situation is particularly complicated for stateless persons.

The arrested man told the authorities in North Rhine-Westphalia, where the attacker from Brokstedt initially lived, that he came from the Gaza Strip. "Repatriations to the autonomous Palestinian territories were very rare in the past," said a spokesman for the Federal Ministry of the Interior when asked. And: "Return options must be carefully examined in advance against the background of the complexity."

The knife attacker from the regional train was granted subsidiary protection in 2017 - the protection that applies when neither refugee protection nor the right to asylum can be granted and people in their country of origin are threatened with serious harm. In 2021, a procedure to revoke subsidiary protection was initiated. The authorities in Schleswig-Holstein have not yet announced whether the reason for this procedure was the extensive criminal record of the 33-year-old.