In California Girl, T. Jefferson Parker crafts an atmospheric, melancholy murder mystery against the backdrop of the changing tapestry of California and life in the 1960s. The "winds of change" are sweeping the country, as fears of Communism linger but are simultaneously subsumed in the burgeoning "new consciousness" challenging the status quo regarding war, music, sex and drugs. These themes are never more evident than in Parker's use of such characters as Richard Nixon, Timothy Leary, and Charles Manson as bit players in the unfolding drama that begins when the beheaded body of young Janelle Vonn is discovered in an abandoned orange-packing plant.

Only Janelle Vonn's death isn't really the "beginning," at least not for the Becker brothers whose lives are entangled in her death. David, Andy, and Nick first met Janelle when she was five years old and they were "rumbling" with her brothers. Their lives intersected at other brief moments as well: for example, a Thanksgiving dinner shortly after Janelle's mother killed herself with rat poison, when recently ordained minister David thought it appropriate to invite the Vonns over for a meal. And then later, when she visited David's "drive in church" and revealed the ugly details of abuse and incest at the hands of her older brothers, crimes which local cop Nick investigated and which Andy the reporter covered for the local newspaper.

As such, Nick is shocked when he steps into the abandoned warehouse on his very first homicide investigation and discovers that he knows the victim. Andy, now a crime beat reporter, is likewise surprised - and their simultaneous investigation of her death also draws David into the mystery as well. Only nineteen, Janelle was an enigmatic cipher, embracing the free love messages of gurus like Leary (and his LSD as well), while at the same time leading something of a double life as a potential police informant. She'd won a local beauty pageant only to be stripped of her title after she posed for the cover of Playboy (and showed less skin on that cover than she did in her bathing suit, at least according to those who'd seen both). She took occasional modeling jobs, was going to school, and seemed to have far more in the way of "stuff" than most supposedly penniless teenagers should have.

The investigation into her death begins with the discovery of a transient nicknamed "the Wolfman" in the press, but he is quickly dismissed as a viable suspect. As Nick and Andy delve further into Janelle's life, they find themselves at an odd intersection of California in 1968: a world featuring an often-uneasy mixture of John Birch Society paranoia, anti-war protesters, free-love radicals, tripping musicians, and the developing hard core of the burgeoning drug trade.