He was played by actor Johnny Lee Miller.
The titular Mindhunters are a group of young FBI students who are undergoing training as profilers. They travel with their instructor Jake Harris (Val Kilmer) to a small island off the coast of North Carolina in order to complete a profiling exercise. The island is used as a training facility by the FBI and the military where a mock town has been constructed. Harris has arranged an elaborate training scenario for his students whereby their mission is to create a profile of a serial killer who has committed a murder in the town.
The students include Bobby (Eion Bailey), a young man with a talent for fixing things; Vince (Clifton Collins Jr.), a wheelchair-using ex-cop who goes nowhere without his gun; Nicole (Patricia Velasquez), a smoker who is attempting to quit; Sara (Kathryn Morris), a talented but insecure profiler who is also petrified of drowning; Gabe (LL Cool J, listed as James Todd Smith), an outside observer; Rafe (Will Kemp), a very intelligent, caffeine-powered British investigator; Lucas (Jonny Lee Miller), a supposedly fearless man whose parents were killed when he was a child; and J.D. (Christian Slater), their leader and Nicole's lover. Vince tells Sara that he has seen evaluation sheets in Harris' office and knows that he and Sara have been performing poorly and both are considered very unlikely to pass and become profilers.
They arrive on the island and commence their investigation the following day. The group first finds a dead cat with a watch- frozen at 10:00- shoved into its mouth. At 10:00 in the morning the group finds the first staged crime scene and encounters an elaborate, Rube Goldberg or Heath Robinson style trap. J.D.'s position as leader of the group prompts him to investigate it more closely, and he is promptly killed by it. Convinced that his death is not part of the training simulation, the group heads to the dock to leave the island. They fear that a killer is on the island with them. Their actions trigger another trap, this one destroying the boat they were going to use in order to escape. While recuperating from the last trap, Rafe makes some coffee which turns out to be drugged, knocking everyone out. When the group awakes, they discover that Rafe has been decapitated and exsanguinated while unconscious and that the killer has painted an elaborate group of numerical ciphers using Rafe's drained blood and the group also finds a pair of broken watches. As the time indicated on the broken watches approaches, the group discovers that the cipher refers to the speed of light.
At first, suspicions seem to point to Gabe. He temporarily deflects these suspicions when he saves Vince from another trap involving broken water pipes and lights electrocuting the water. When Bobby attempts to shut off the water, another trap triggers; firing arrows into his head and killing him. Later, the results of a blood analysis collected from scraped skin samples found under Rafe's fingernails point to Sara, who denies being the killer; Lucas supports her. Nicole ultimately decides she cannot trust any of her colleagues and leaves while holding the others at gunpoint, resulting in her death; the stress of the situation causes her to relapse into her smoking addiction and while walking outside, she finds spontaneously vended pack of cigarettes. She steps out to smoke one and quickly learns that it has been laced with a strong acid, which eats her alive from the inside as Gabe and Lucas stare on in horror. Sara, meanwhile, finally deduces that the traps are based on their strengths, talents, and weaknesses and the remaining profilers elect to stick together, to keep an eye on each other.
Unexpectedly, the island's speakers begin to broadcast a taunting message from Harris, making them realize that he did not leave the island, though he led the profilers to believe that he had; convinced that he has been the killer all along, they search for him. Vince refuses to join the search party and stays behind at the lab. Sara, Gabe and Lucas find Harris and two other FBI agents next to him, all dead; Harris has been strung up to wires from the ceiling as a sort of marionette, just like the fake crime scene that they were to investigate. The three survivors realize that the killer is one of them, and in the shootout that ensues, Gabe seemingly takes out Lucas. At the same time, Vince manages to crawl to an elevator but hears someone coming toward him. He fires his gun (he always keeps it handy after having been shot earlier as a cop) at the stranger, but it has been tampered with by the killer and explosively misfires, sending shards into his face and arm and killing him.
Gabe and Sara then confront each other, each believing the other to be the serial killer. Lucas, who was wearing a bullet-proof vest, returns and jumps Gabe from behind. The two violently attack one another, eventually falling through a glass ceiling. Gabe starts to get up but is knocked unconscious by Sara, who then begins to tend to Lucas. Sara explains she figured out the killer's fascination with time and need to keep a schedule and she adjusted the clock in the lab and placed a powder marker on the clock. The clock has since been adjusted by the killer, and the powder will tell them who the killer is. Sara finds the marking powder on Lucas' hands instead of Gabe's. Lucas confesses that he killed his parents and has been seeking more thrilling targets to kill through the rest of his life, leading him to join the FBI and plan to kill his brilliant fellow profilers. Lucas tries to drown Sara, but she manages to kick him into the water. They realize that an underwater gun fight will not work, that they need to shoot above the water so they hold their guns above the surface and see who is able to hold their breath longer. Lucas fails and goes to take a breath, during which Sara wounds him badly. Lucas begins to taunt her about the evidence he planted blaming her, until Gabe reappears: he is the last witness. In a last desperate effort, Lucas attempts to regain his weapon, forcing Sara to kill him.
The film ends with Sara and Gabe flagging down a helicopter together. As they move to board, Sara wonders whether or not she has achieved profiler status.