The Blinds by Adam Sternbergh

Imagine a place populated by criminals—but ones who have opted into an experimental programme to win new identities and a second chance, their violent memories erased. Welcome to The Blinds, a dusty town in rural Texas populated by misfits who are no longer sure if they perpetrated a serious crime or just witnessed one. What they do know is that if they ever try to leave they will end up dead.
For eight years, Sheriff Calvin Cooper has kept an uneasy peace—until, that is, a suicide and a murder occur in quick succession, raising dangerous questions and bringing mysterious outsiders to his forgotten town.
Simmering with violence, heartbreak and deception, heartbreak and betrayal, The Blinds is a provocative, keenly intelligent thriller which lingers long in the memory.