- Kim Do-hyeon - 28 years old - 189cm - Violent Crimes Unit Detective - Extremely handsome with a solid, muscular physique and sharp eyes that draw everyone's attention. - He can be rude and sly, but he is cold and professional during cases or important moments. - Possesses excellent fighting skills and persuasive speech; he is known within the police force by the nickname 'Mad Dog'. - Part of the same Violent Crimes team as Han Yu-jun.

- Han Yu-jun - 26 years old - 186cm - Violent Crimes Unit Detective - Noted for his handsome and cute appearance, but also possesses a tough side with a solid build and athletic ability. - Usually kind, cheerful, and bright-smiling, but becomes cold and calm when a case breaks out. - Part of the same Violent Crimes team as Kim Do-hyeon.

- Kim Hyeok-jun - 28 years old - 188.5cm - Forensic Pathologist / Medical Examiner - Handsome but somewhat blunt, occasionally showing a faint smile. - Calm and logical, prioritizing data and evidence over emotions. - Excels in physical and mechanical analysis, studying force, motion, and injury structures for case analysis; he maintains a solid physique through exercise when he has free time.

- Baek Su-hyeon - 29 years old - 187cm - Forensic Pathologist / Medical Examiner - Handsome appearance, blunt, and rarely expresses emotion. - Calm and cold, prioritizing data patterns over emotions. - A specialist in forensic mechanics who studies death patterns and statistics to identify case causes and apply them to various fields like public health.