German police arrest 15-year-old for killing classmate

German police have arrested a 15-year-old schoolboy suspected of killing a classmate on Tuesday by stabbing him in the neck, authorities and media reports said.Media reports said the teenager did not resist when police tracked him down through a helicopter search and arrested him.Prosecutors said preliminary investigations suggest that the boy was not planning a rampage at the school in the western state of North Rhine-Westphalia.