Shawn Holloman is the older brother of Will, who is shot and killed at the start of the novel. He followed The Rules of street life, having previously avenged the death of his mentor Buck. Shawn's memory and influence weigh heavily on Will's decisions.

Will and Shawn's mother struggles with grief after Shawn's death. Her skin condition, eczema, worsens under stress, symbolizing the collective pain carried by mothers in their community.

Carlson Riggs, a childhood friend of Shawn, is suspected by Will of having murdered his brother. Riggs is described as having a loud mouth, aspiring to be tough, and is associated with the Dark Suns gang.

Buck is Shawn’s mentor, who looked after him after Shawn’s father died. A petty thief with a preacher for a stepfather, Buck was killed by Frick during a robbery. His death prompts Shawn to seek revenge using Buck's gun.

Dani is Will's childhood crush and first kiss. She was killed in a neighborhood shooting when they were both young children. Dani’s presence reminds Will of the innocent lives affected by violence.

Uncle Mark is Will’s deceased uncle and the brother of Mikey Holloman. He was a cinematographer whose shift to drug dealing led to his death. Uncle Mark challenges Will to envision the consequences of revenge.

Mikey Holloman, Will’s late father, shares his own tragic story with Will during the elevator ride. Mikey’s actions after Mark’s death are intended to teach Will about the cycle of violence and its repercussions.

Frick was responsible for killing Buck during a gang initiation, an act that later resulted in Shawn avenging Buck's death. Frick is portrayed as unapologetic, surprising Will with the lack of seriousness others give to the story.