Mickey Fitzpatrick is a 31-year-old veteran patrol officer in the Philadelphia Police Department. She works in Kensington, the poverty-stricken neighborhood where she grew up. Mickey raises her young son, Thomas, and structures her life around strict boundaries and rules to maintain stability. She actively uses her position on the force to keep a watchful eye out for her estranged younger sister.

Kacey Fitzpatrick is Mickey's younger sister. She lives on the streets of Kensington and struggles with severe drug addiction. From a young age, Kacey exhibits an outgoing, rebellious personality that frequently invites trouble. She turns to prostitution to support her drug habit and completely ceases contact with her older sister.

Gee O'Brien is the grandmother of Mickey and Kacey. She assumes custody of the girls after her own daughter dies of an overdose. Working multiple jobs to keep the family afloat financially, she provides basic necessities but operates a cold, unloving household. She actively discourages the girls from pursuing higher ambitions.

Simon Claire is a charismatic police officer who mentors at-risk youth in Kensington. He takes an early interest in a teenage Mickey, eventually advising her on career choices and becoming her romantic partner. He later marries another woman and starts a new family, creating intense tension with Mickey.

Truman Dawes is a veteran police officer and Mickey's partner of ten years. He is currently recovering at home after a masked assailant shattered his kneecap with a baseball bat. He acts as a father figure to Mickey, offering her practical advice and serving as one of the few men she implicitly trusts.

Thomas Fitzpatrick is Mickey's young son. Approaching five years old, he is tall, strong, and highly intelligent. He attends a school for gifted children until financial constraints force Mickey to move him to a less expensive program. He remains isolated from Mickey's extended family for much of his early life.

Eddie Lafferty is a rookie police officer temporarily assigned to partner with Mickey. He talks constantly during their shifts and frequently dismisses the local overdose victims as unimportant. Mickey takes an immediate, instinctual dislike to him and soon requests to work solo.

Sergeant Ahearn is Mickey's immediate supervisor in the police department. He exhibits little concern for the deceased women of Kensington and routinely dismisses Mickey's investigative instincts. He feels intimidated by Mickey's serious demeanor and prefers officers who follow his relaxed standards.

Mrs. Mahon is Mickey's neighbor in her new apartment building. An ex-nun who left the convent to marry, she is observant and kind. She frequently steps in to watch Thomas when Mickey's regular childcare arrangements fail.

Dock is a Kensington local involved in the neighborhood's drug trade. Mickey identifies him through Kacey's social media as her sister's most recent boyfriend. He operates out of an abandoned house and maintains aggressive boundaries regarding his business.

Paula is a sex worker operating in Kensington and a known associate of Kacey. Though generally friendly with Mickey, she maintains the neighborhood's standard wariness toward police officers. She provides Mickey with crucial street-level rumors regarding the recent murders.

Davis Nguyen is a detective in the Homicide division. He leads the official investigation into the murdered women in Kensington. He coordinates the search for suspects based on security camera footage and local tips.

Mike DiPaolo is a Homicide detective investigating the Kensington murders. Truman vouches for him as one of the few trustworthy officers in the department. He shares confidential updates on arrests with Mickey off the record.

Cousin Ashley is part of Mickey's extended O'Brien family. She is the same age as Kacey and shares a strong physical resemblance to her. She hosts large family gatherings where the relative success and failures of family members are quietly judged.

Cousin Bobby is a younger member of Mickey's extended family. Like several of his relatives, he struggles quietly with drug use. When Mickey asks for information about Kacey's dangerous boyfriend, Bobby promises to ask around the neighborhood.

Alonzo owns a local convenience store in Kensington located near the corner where Kacey typically works. He knows the regular street workers by sight and provides Mickey with the concerning news that Kacey has been missing for a month.