H Is for Homicide by Sue Grafton

It started with the murder of Kinsey Millhone's sometime drinking buddy, an insurance claims adjuster. But before long Kinsey stumbles onto a massive insurance scam. Going undercover as a wisecracking vamp, Millhone descends into the Los Angeles nether world of machismo and gang hideouts. Her companion, terrified at having crossed the violent crook Raymond Maldonado, is Bibianna Diaz, no Girl Scout herself.