LONDON - Detectives hunting the brutal killer of Mrs Lin Russell (42) and her daughter Megan (6) yesterday arrested a local man. The man, in his 30s, is being questioned by detectives at an unnamed police station, a police spokeswoman said. Detectives were not saying where the man was arrested. The mother and daughter were bludgeoned to death as they walked home along an isolated footpath near Chillenden, near Canterbury, Kent, from a school swimming gala on July 9th.