California Girl by T. Jefferson Parker

Set on Parker's usual turf, this Orange County, Calif., saga is a family drama carefully wrapped around a mystery involving a murdered beauty queen. Back in 1954, the Becker brothers, David, Nick, Clay and Andy, win a fight with the wrong-side-of-the-tracks Vonn brothers at the Sunblesst orange packinghouse. After the rumble, the Vonns' little sisters, Lynette and Janelle, show up to throw rocks. Thus begins a lifelong association between three of the brothers and the two girls. In 1968, Janelle is back at the packinghouse, only now she's lying dead on the floor, her decapitated head several feet from her torso. Nick is with the county sheriff's department working his first case as lead detective. Brother Clay has been killed in Vietnam, Andy is a reporter on a local newspaper and David is a minister.