Angie is a former art teacher living in Lodgepole, Colorado, who left her career to become the full-time caregiver for her chronically ill son, Nico. She harbors intense anger toward her daughter, Nora, for the shooting and refuses to offer her support in the holding cell. The tragedy causes her marriage to David to fracture entirely as they argue over responsibility. She also shares a complicated past with Julian Dumont, her high school sweetheart.

David is a law enforcement officer for the National Parks Service who prefers outdoor activities like hunting and hiking. He uses his connection to local attorney Martine Dumont to secure a discounted rate for his daughter's defense. He remains fiercely protective of Nora, visiting her frequently in detention while his wife stays away. His marriage deteriorates as he and Angie argue over his unsecured service weapon and her clear favoritism.

Nora is a 13-year-old artist and the youngest person ever held in the Lodgepole county jail. Following the fatal shooting of her older brother, she withdraws completely, refusing to speak or explain her motives. She endures a harsh environment in the juvenile detention facility, suffering from cold temperatures, bullying, and severe depression as the district attorney pushes to try her as an adult.

Nico is a 14-year-old boy whose recent diagnosis with juvenile Huntington's disease devastates his family. Before his illness, he was an athletic teenager who loved skiing and studying birds. His sudden death at the hands of his sister serves as the central tragedy of the story, leaving his parents to process the loss of a boy who was desperate to maintain a normal life.

Martine is a 72-year-old defense attorney in Lodgepole who is eager to retire from her demanding career. She agrees to represent Nora at a discounted rate due to her historical ties to the Sheehan family. Possessing a strong sense of empathy, she worries about the public vitriol aimed at her client. She recruits her estranged son to assist with the complex homicide trial.

Julian is an experienced criminal defense attorney based in New York City who specializes in pro bono cases. He left Lodgepole decades ago following a fatal skiing accident and maintains very little contact with his mother, Martine. He struggles with alcohol use stemming from unresolved guilt about his past. Returning to Colorado to co-counsel Nora's case brings him back into contact with his high school girlfriend, Angie.

Gil is the district attorney for Lodgepole, currently running a difficult re-election campaign. He adopts a rigid, tough-on-crime stance to appeal to voters. He views the Sheehan case as an opportunity to demonstrate his strict policies, threatening to try Nora as an adult and initially refusing any plea deals.

Livia is an Italian immigrant who co-owned a successful restaurant in Lodgepole with her husband. She currently resides in a memory care facility due to late-stage Alzheimer's disease. Before her cognitive decline, she was known for her unyielding nature and inability to forgive, particularly harboring a lifelong grudge against Julian Dumont following her youngest daughter's death.

Roberto is Angie's father, remembered through flashbacks as a supportive and hardworking restaurant owner. He provides a stark contrast to his wife's rigid personality. He approaches people with warmth and refuses to pass judgment on his daughter's life choices. His battle with cancer severely impacts his family's stability.

Diana is Angie's younger sister who died at age seven in a skiing accident decades before the main events of the story. Her sudden death fractured the friendship between the DeLuca and Dumont families and continues to shape the emotional lives of both Angie and Julian.

Jacqueline is a quiet inmate housed in the same juvenile detention center as Nora. Like Nora, she refuses to speak for much of her incarceration. She faces a lengthy sentence following a violent response to extreme family abuse, illustrating the difficult backgrounds of many youth offenders in the facility.

Maria Elena is a youth offender serving time for armed robbery at the juvenile detention facility. She establishes dominance by stealing newly issued clothing and toiletries from incoming inmates. She targets Nora, bullying her over her middle-class background and private legal representation.

Paradise is a repeat offender housed in the Lodgepole juvenile detention center. She is incarcerated for selling illegal drugs manufactured by her aunt. Her presence highlights the cycles of poverty and familial exploitation that trap young people in the justice system.

Mayumi is Julian Dumont's supportive wife who lives in New York. She provides him with a stable foundation and encourages him to view people's mistakes with compassion. Her healthy pregnancy brings joy to Julian's life as he manages the stress of returning to his hometown.

Cyrus is Martine's late second husband and a former general physician in Lodgepole. He ran a thriving family practice and provided a stabilizing, loving presence in Martine's life after her first husband's death. He helped raise Julian during his teenage years.

Gregory is the son of Martine and Cyrus, raised in Lodgepole as part of their blended family. He grew up as a healthy, well-adjusted child, shielded from much of the trauma that affected his older half-brother.