"Crime Squad" focuses on a group of detectives in the Seoul Gangnam Police Homicide Division led by the hotheaded detective Park Se-hyuk and the cold, commanding police chief, Jung Il-do. Park Se-hyuk and Jung Il-do are much different in working style, but they share a painful past, with Il-do being the detective on the case involving the death of Se-hyuk's daughter. Therefore, they try to overcome their differences to lead the homicide squad to solve crimes.