A bloodstain by a bridge over the Seine river was the only remaining sign on Sunday of a fatal knife attack 12 hours earlier on a German tourist, allegedly carried out by a young man under watch for suspected Islamic radicalization.
The random attack near the Eiffel Tower has drawn special concern for the French capital less than a year before it hosts the Olympic Games, with the opening ceremony due to take place along the river in an unprecedented scenic start in the heart of Paris.
