Sullivan is a Berkeley police detective of Mexican, Jewish, and working-class heritage who passes as white by using his mother's surname. He joined the police force to stay above the "suspicion line" after his father was deported during the Mexican Repatriation. He relies on rational, evidence-based methodology while managing difficult relationships with his prejudiced superiors.

Isabella is one of three wealthy Bainbridge granddaughters. She survived severe childhood trauma after discovering her sister's body at the Claremont Hotel, an event that left her temporarily mute. She works as a reporter and uses flirtation, deception, and theatrical behavior to control conversations and deflect police scrutiny.

Mrs. Bainbridge is the matriarch of a wealthy San Francisco Bay Area family. She provides a sprawling written testimonial to the district attorney to control the official narrative of her family's history. She views herself as the ultimate protector of her descendants and uses her social status to intimidate law enforcement.

Wilkinson is a charismatic industrialist and former presidential candidate. He projects a progressive, respectable public image that actively conceals a history of reckless philandering and moral corruption. His murder sets the entire investigation in motion.

Sadie is Genevieve's daughter and the mother of Isabella and Iris. Once famous for her striking beauty, she suffered from severe postpartum depression and addiction following personal tragedies. She eventually underwent a lobotomy, leaving her in a compromised mental state that requires constant supervision.

Nicole is a university student who rebels against her family's wealth by embracing communist ideology. She participates in picketing and political activism, though her grandmother views her convictions as naive and performative. She becomes an early suspect in Wilkinson's murder due to her radical politics.

Cassie is the most pragmatic of the Bainbridge granddaughters. Described as a "natural huntress," she possesses practical outdoor skills and an unwavering loyalty to her loved ones. She takes direct action to protect vulnerable people, often putting herself at significant legal risk.

Miriam is Sullivan's 11-year-old biracial niece. Because she cannot pass as white like her uncle, she faces overt discrimination at school. She works after school at a local store to pay rent and manage her mother's severe gambling debts, forcing her to grow up far too quickly.

Iris is Isabella's older sister who died at age seven after falling down a laundry chute. Her tragic death shatters the Bainbridge family and serves as the dark anchor for the events occurring fourteen years later. She is heavily associated with a damaged Dy-Dee doll found at the 1944 murder scene.

Doogan is the ambitious District Attorney prosecuting the Wilkinson murder case. He pursues the investigation aggressively for political gain, readily shifting his theories and targeting vulnerable populations without concern for actual guilt.

Juanita is a working-class Mexican maid at the Claremont Hotel. Her shifting testimony regarding what she saw outside Wilkinson's room on the night of the murder makes her a crucial but unreliable witness. She is highly vulnerable to police intimidation.

Yuko is a Japanese American woman forced to hide from the government to avoid placement in an internment camp. She and a group of Japanese workers attempt to pass as Chinese at the Claremont Hotel to survive the racist wartime policies.

Roger is Sadie's husband and Isabella's nominal father. He is defined by profound bitterness and resentment toward his wife and family, actively warning investigators not to trust his own daughter.

Greening is Sullivan's boss at the Berkeley police department. He represents an older, complacent form of law enforcement, readily deferring to wealthy citizens while expressing casual antisemitic and racist prejudices.

Sal is a working-class shipyard worker in Richmond and a communist activist. His political involvement and relationship with Nicole Bainbridge draw the attention of the police, leading to false confessions and tangled alibis.

Eliana is Sal Ibarra's cousin. She holds deep resentment toward Nicole Bainbridge, viewing her political activism as condescending while simultaneously using Nicole for financial gain.

Madame Chiang is the elegant and charming first lady of China, currently living in Berkeley. She denies any involvement in the murders while attempting to manage political optics and secure the release of her loyalists.

Jane Chao, whose actual name is Shirley Wang, is a former servant of Madame Chiang Kai-Shek. She is found brutally murdered in her public housing apartment, drawing local Chinatown factions into the broader investigation.