After the tragic death of his partner, a plainclothes detective, Thomas "T.J." Hooker returned to his old job as a patrol sergeant with the aim of ridding the streets of crooks like those responsible for his partner's death. Hooker was tasked with training recruits at the academy and was paired with a cheeky and sometimes overly impulsive young recruit Vince Romano. With a partner much younger than himself, Hooker acted as a mentor both on the job and in everyday interactions. The age difference proved to be the key to excellent teamwork, and the pair quickly became close friends and a solid team.