Marquis is accused of involvement in the murder of a man from a rival neighbourhood. Darren has been found guilty of murdering a petrol station attendant. Charles has been charged with the murder of a homeless teenage girl. All of them are potentially facing the death penalty in California. Australian-born Rachel Sommerville is a private investigator whose job is to help lawyers convince a jury or appeal court to let these men live. Her search for the evidence that may stop the imposition of a death sentence takes her to some of the most disadvantaged neighbourhoods in the US. California P.I. is Sommerville's passionate account of the men whose lives she tries to save and of her journey from genteel, middle-class Adelaide to the ghettos and prisons of America.