"I is for Innocent" is a mystery novel by Sue Grafton featuring the iconic private investigator Kinsey Millhone. In this installment of the Alphabet series, Kinsey is drawn into a complex case involving the past and the wrongful accusation of murder. The story begins when Kinsey is approached by a man recently acquitted of his wife's murder after a lengthy trial that has left him ostracized and desperate to clear his name.