Martin Brody is the elected chief of the Amity Police Department. He embodies the rule of law and, to many of the local people, he is the physical representation of the enforcement of these rules. On a personal level, Brody is a man of limited ambitions. Unlike his wife, he never thinks beyond the town limits of Amity and his commitments are defined by his desire to help the local people survive. He is occasionally willing to overlook small infringements of the law to support the faltering economy of Amity, so long as he can ensure the peaceful running of his town. As such, Brody is a man of compromise. This notion of calm compromise is challenged by exceptional circumstances, to the point where he must choose between people's safety and the long-term survival of Amity. The arrival of the shark forces Brody into making difficult decisions which challenge his. He initially sees himself as relaxed, flexible, and in control, but the shark changes that, as well as everything else.

The shark represents a world beyond Brody’s. The shark is not just from outside Amity, it’s from the unknown depths of the ocean.