The cops have a definite clue when a bloodstain that's not the same as the victim reveals that the killer was a blood relative, and the prosecutors stumble when their chief suspect claims their chief witness is her lawyer, and his knowledge of the crime represents privileged communications.

Bloody sheets and an apparently stolen credit card lead Briscoe and Curtis to a pair of college age lovers who present McCoy and Ross with a united front of denial that one of them killed their newborn son and disposed of the body.

After the detectives find a murdered postman and a woman who was left for dead in her apartment, the investigation leads to a serial killer and a surprise.

After sanitation workers find a teenage boy's body, the investigation leads to a school bully who displays an avid interest in martial-arts weapons, and whose father bought the murder weapon.