In January 2001, a bomb exploded in a small grocery store on Probsteigasse in Cologne. The owners’ 19-year-old daughter was seriously injured. The attack remains unsolved – a phantom photo leads to an undercover agent from the Federal Office for the Protection of the Constitution. A lead that was never really followed. And which still raises questions today. Above all: How big was the terrorist group really?
The article first appeared in stern 04/2018 and has been updated.