Episode 301, "One Wrong Move"
SEASON 3, EPISODE 308 - A young man appears to be the victim of a crime, and is thought to be taken hostage. The SRU team is brought in to find him after his captor carjacks a woman, whose baby is also in the car. They hide out in a hotel room while SRU tries to figure out how to burst into the room without hurting the baby. Jules investigates the boy's life, and finds that he is a deeply disturbed psychopath who has no empathy for other human beings. He is actually acting as if he was kidnapped, but quoting famous serial killers, he is planning his first kill.