Eva is an Armenian-American woman who formerly ran a successful bohemian travel guide company called A Wing and a Prayer. She now lives an isolated life, making regular visits to a juvenile detention facility to see her son. Deeply observant and occasionally cynical, she writes extensive letters documenting her marriage and her son's upbringing. She harbors profound ambivalence regarding motherhood and attempts to understand her own culpability in her family's tragedy.

Franklin is Eva's estranged husband, who works as a location scout for advertising photography. He is an optimistic, patriotic American with traditional ideals about family life. Desiring a happy and conventional home, he is fiercely loyal to his son and desperate to bond with him. He frequently defends the boy against Eva's criticisms, remaining willfully blind to the hostility she experiences when he leaves the room.

The firstborn son of Eva and Franklin, currently serving time in a juvenile detention facility for an atrocious crime. From infancy, he exhibits a cold, manipulative demeanor and aggressively rejects his mother's attempts to care for him. He is highly intelligent and views the world with profound nihilism, finding ways to systematically alienate caretakers and peers while maintaining a falsely innocent facade for his father.

The younger sister of Kevin, born after Eva makes a unilateral decision to have a second child. In direct contrast to her brother, she is sweet, affectionate, and easily pleased. She possesses a gentle nature and unconditionally adores her family, an innocence that leaves her highly vulnerable to quiet cruelties.

A grieving community member who lives near Eva's new apartment in Gladstone. As the mother of one of the high school students involved in the tragedy, she harbors intense bitterness toward the Khatchadourian family. She files a civil lawsuit against Eva, serving as a persistent reminder of the town's collective anger.

Mary's daughter and a student at Gladstone High. She struggles with an eating disorder, an insecurity that attracts unwanted, critical attention from her peers.

An unpopular student at the high school who gravitates toward Kevin. He acts in a highly obsequious manner around his peer, willingly participating in vandalism and serving as a loyal subordinate in their shared misdeeds.

An English teacher at the high school who refuses to be intimidated by serene facades. She recognizes the deep anger beneath the surface of her students and openly confronts manipulative games rather than ignoring them.

An eccentric drama teacher at the high school whose passionate approach to education makes her a target. Her boundary-pushing teaching style and enthusiasm for theater provide ammunition for students looking to exploit her professional standing.

An Irish nanny hired to care for the household's firstborn. She initially attempts to manage the domestic responsibilities but is quickly worn down by relentless shrieking and destructive tantrums, eventually resigning for the sake of her own well-being.

Eva's attorney during the civil proceedings brought against her by angry community members. He treats the law primarily as a strategic game, urging his client to settle without understanding her psychological need to face the consequences in court.