All Unwary by Clare Curzon
May Matsukawa, a half-English, half-Japanese girl, runs away from her boarding school. Her parents are close to estrangement, and when she turns up at her mother's house, her father, a multi-millionaire, sends a business associate to escort her back to school, she becomes increasingly distraut. When this man is found murdered in a nearby hotel the first question asked by Mike Yeadings and his colleagues in the Thames Valley police is - could May be a killer? Or is it more likely to have been May's mother? Or was it some other party who'd mistaken him for Matsukawa himself?