It's a book about voice and voicelessness. The central crime silences a victim. The plot is the struggle to give that victim a voice posthumously, through evidence and testimony. The theme is the ethical imperative of listening to marginalized stories, of breaking the conspiracy of silence that protects the powerful.
Each character grapples with whether to speak up, at what cost. The novel suggests that silence is a form of complicity, but also acknowledges the real dangers of speaking. It's a nuanced take on a classic moral dilemma, refusing easy answers.