Killer Instinct

Dean, like Cassie, is a gifted profiler and one of the teenagers in the FBI’s Naturals program. His father is Daniel Redding, a prolific serial killer now serving a life sentence, and Dean’s struggle to come to terms with his own identity is central to the novel’s depiction of Biological Heritage Versus Found Family. He grew up with a father who kidnapped, tortured, and killed women, ultimately involving Dean in his violent rituals. When Redding abducted agent Sterling, who was investigating him at the time, Dean and Sterling came up with an escape plan together. After Redding was apprehended, Dean was brought into the FBI and became the first member of the Naturals program, but despite his efforts to atone for his father’s crimes, Dean feels guilt and self-loathing that generally manifest as internalized anger, lending further weight to his fears that he resembles Daniel Redding. 

Dean is described as having “Chocolate-brown eyes [that] sparkle underneath the blond hair that [hangs] perpetually in his face [and a] dimple […] in one cheek” (7). He is one of Cassie’s romantic interests and often relies on her for moral support. However, Dean tends to isolate himself when he is upset because he is afraid of hurting others. At first, Dean is unsure about pursuing a relationship with Cassie because of his own trauma. However, he eventually confesses his feelings for her, and the two of them kiss after Cassie is rescued from Webber.

Michael is a Natural whose particular talent is to “read facial expressions as easily as other people read words” (4). He developed that skill because he grew up with a violent, abusive father and needed to anticipate his moods to protect himself. Throughout the story, Cassie often comments on Michael’s uncanny ability to uncover her most secret emotions despite her attempts to hide them. However, unlike her, Michael does not necessarily understand what causes those emotions in people or their deeper motivations.

Michael is one of Cassie’s two romantic interests and is introduced as Dean’s foil. Unlike Dean, Michael is spontaneous, sometimes reckless, and often acts as comic relief during tense moments in the story. Even apart from their shared feelings for Cassie, the two boys have a very conflictual relationship because Dean represses his feelings for fear of losing control of his anger while Michael tries to draw emotions out. Cassie explains that “Michael’s defense mechanism growing up had been to recognize anger, and if he couldn’t defuse it, to provoke it” (209), which explains his repeated attempts to antagonize Dean.

Like Dean, Michael is also very protective of Cassie. While they are in Broken Springs, he asks her to choose between him and Dean, stating, “You want me to tell you what you feel. I want you to know” (249). When Cassie eventually picks Dean at the end of the novel, Michael appears disappointed and angry, and Cassie is afraid that their relationship may suffer for it.

Lia is part of the Naturals program, with her special talent being the ability to tell truth from lies. Although the novel says little about her past, Cassie gradually learns that Lia likely grew up in a traumatic environment that gave her an uncanny ability to notice deceit: “Lia’s [defense mechanism] had been to bury herself away under so many layers of deception that whatever anyone else did to her, they couldn’t really hurt her, because they couldn’t touch the real girl” (209-10).

Lia is prone to explosive anger and recklessness and is sometimes cruel and manipulative. She does not trust anybody except Dean, with whom she has a sibling-like bond—the result of shared history, as they were the first to be inducted into the Naturals program. Lia’s desire to protect Dean drives many of her actions, including her antagonism toward Cassie. However, she realizes that Dean trusts Cassie and gradually warms up to her over the course of the novel, even opening up about her past and her relationship with Dean.

Sloane is the fifth member of the Naturals program and is described as having long white-blond hair. She is extremely good with facts and statistics and is able to mentally compute numbers and schematics quickly and efficiently. Her talent extends to cataloging the world with mathematical precision: Cassie comments that after seeing a brief clip of crime scene footage, Sloane has “encoded every last numerical detail: the length and width of the rope tied around the victim’s neck; the exact positioning of the body; the height of the grass; the make, model, and specs of the car” (77).

Sloane is depicted as the least socially adept of the five teenagers. She often struggles to identify other people’s emotions or understand their motivations, which occasionally leads to misunderstandings. When Cassie silently signals Sloane not to share information with Sterling, for example, Sloane interprets Cassie’s gesture in the opposite way. Sloane is also characterized as somewhat insecure, as when she points out that Lia and Cassie did not include her in their trip to Colonial University. Cassie makes a point afterward to include Sloane in their plans, and Sloane opens up more. At the end of the story, Sloane is the one who remembers Cassie’s tracking anklet, which proves crucial in rescuing Cassie and Sterling.

Special Agent Veronica Sterling is FBI Director Sterling’s daughter as well as Agent Briggs’s ex-wife. She was assigned to supervise and assess the Naturals program after Locke’s death in The Naturals, and she initially appears hostile toward the five teenagers, as well as strict and authoritative. This prompts Cassie to note that Sterling has “clearly cast herself in the role of enforcer” (82), establishing the initially antagonistic relationship between her and the teens she supervises.

Sterling’s physical appearance serves as indirect characterization: She is “tall and thin, but nothing about her seem[s] slight. Her dark brown hair [is] pulled into a tight French knot at the nape of her neck, and she [holds] her head with her chin thrust slightly forward. […] Her clothes [are] expensive; she [wears] them like they [aren’t]” (19-20). Her posture suggests self-assurance and assertiveness, while her strict-looking suits echo her severe demeanor. However, Dean reveals that Sterling used to be more impulsive and reckless: “She had a hot temper, and she followed her gut, even when that wasn’t the smart thing to do” (42). Sterling’s temperament makes her a good FBI agent but caused her to temporarily leave the Bureau after her friend Scarlett Hawkins, Judd’s daughter, was killed during an investigation.

Sterling is very protective of Dean, with whom she bonded during the investigation into his father. Over the course of the story, she also learns to trust the other four teenagers and even tells Cassie that she sees herself in her. Initially, Sterling is set on shutting down the Naturals program, convinced it is detrimental to the teenagers’ well-being. However, she eventually comes around and instead implements more robust checks and balances to ensure the teenagers’ safety. At the end of the novel, she appears more confident, relaxed, and optimistic about the Naturals’s future.