Playback (1976)
Playback is a 1976 private investigators book written by Raymond Chandler.
In Chandler's final novel, Marlowe is hired by an influential lawyer he's never heard of to tail a gorgeous redhead, but decides he prefers to help out the redhead. She's been acquitted of her alcoholic husband's murder, but her father-in-law prefers not to take the court's word for it.