What are the motifs in Playing for the Ashes by Elizabeth George?

Protecting the one's you love is a recurring idea. Jimmy Fleming is accused of killing his father when it is discovered he was in Kent the night his father was killed. Jimmy is taken to New Scotland Yard and interrogated. During this interview, Jimmy admits to his own guilt. However, Inspector Lynley quickly sees inconsistencies in Jimmy's confession. Lynley sets out to force Jimmy to tell the truth while using the confession in the press to flush out the real killer.