People Like Us by Dana Mele

Kay Donovan may have skeletons in her closet, but the past is past, and she’s reinvented herself entirely. Now she’s a star soccer player whose group of gorgeous friends run their private school with effortless popularity and acerbic wit. But when a girl’s body is found in the lake, Kay’s carefully constructed life begins to topple. The dead girl has left Kay a computer-coded scavenger hunt, which, as it unravels, begins to implicate suspect after suspect, until Kay herself is in the crosshairs of a murder investigation… Read more.