'B' Is For Burglar by Sue Grafton

Kinsey Millhone has chutzpah! She is one determined detective. Beverly Danziger hires Kinsey to find her sister Elaine Boldt, whom she hasn't heard from or seen for six months. Kinsey's detecting gets her involved in the unsolved murder of Marty Grice and a trip to Florida where she meets eighty-eight year old Julia Ochsner, amatuer sleuth. Things take a turn for the worse when it begins to look like the missing woman may have been murdered. Very good. I liked it a lot.