The Girl I Used to Be by April Henry (Henry Holt & Co. hardcover, 3 May 2016).
When Olivia Reinhart was three years old, her mother was murdered. The primary suspect was her father, but he disappeared.
Flash-forward fourteen years: Olivia is an emancipated minor working in the deli department at a grocery store. She is visited at home by two police detectives who call her by her birth name, Ariel Benson. They inform her that her father's body has been found, in the woods not far from where her mother had been.
In the Medford newspaper, where her family had lived then, she sees a notice for a memorial service, and decides to go, even though she can barely afford the gas to get there from Portland.
Olivia swings by the house where she and her grandmother lived until she died, when OIivia was seven. Seeing that it vacant (and technically, Olivia owns it), she decides to stay for a while to see if she can find out anything about what happened to her parents by getting to know their relatives and friends who are still around.
Although she tries to remain incognito, she's recognized by the elderly neighbor, as well as by her childhood best friend, who agree to assist with her investigation.
What none of them realize is that they are all putting themselves in danger from someone who managed to keep his/her crime a secret for fourteen years, and will do anything to keep it that way.
This is a riveting, fast-paced story that I read in an afternoon.
Ms. Henry is a worthy successor to classic young adult mystery writers such as Joan Lowery Nixon and Caroline B. Cooney.