January was a particularly violent month in Sweden. A 63-year-old man was killed in Stockholm by a hand grenade lying in the street. A Dutch exchange student was hit by a stray bullet during an execution-style killing at a pizza restaurant in Uppsala. In Gothenburg, a hand grenade was thrown into a flat and exploded in the kitchen — the same predominantly immigrant-populated suburb where an eight-year-old British boy was killed in a grenade attack less than two years ago.