The first novel in Sue Grafton's Grafton alphabet mystery series is A is for Alibi. The title of each of the following books in the mystery series begins with the next letter of the alphabet in sequence.
The case begins when a woman, who has recently been released from prison for the murder of her husband, asks Kinsey Millhone to find the real killer. Of course, digging into this old case that the legal system considers solved brings up issues for the people who would have preferred not to remember it.
The next book in the series is B is for Burglar. If you like Kinsey and her friends, you have many more books to enjoy.