Six people lost their lives in a shooting at a youth care centre in the town of Stade, in northern Germany, in one of the country's worst attacks this year. The victims were not those in care, but the centre's staff - people whose job was to look after others.

According to German police, the attack took place on 29 June at a youth welfare facility. The suspect is a 45-year-old man, a Turkish citizen born in Germany, who had come to the centre for a scheduled meeting about custody of his three-month-old daughter. The motive, investigators say, was a custody dispute - his wife and child were living at the facility and were present, but were not harmed.

After the shooting, the suspect tried to flee in a car driven by a 55-year-old woman believed to be close to his family. He was arrested after a brief chase. A second person was also detained. Police did not say whether there had been prior threats or reports - a question that in cases like these always comes too late, when it is already too late.

Germany, like most of Europe, has strict gun laws - and precisely for that reason every tragedy like this leaves the same question unanswered. How did a man in a custody dispute get to a weapon, and to a building full of people? Six families lost their own not in war or in an accident, but at a workplace where the most vulnerable were being cared for. Behind every number like this stands a system that, somewhere, at some point, did not see what was coming.