In 2028, multinational conglomerate OmniCorp revolutionizes warfare with the introduction of robotic peacekeepers capable of maintaining law and order in hot spots such as Vietnam, Iraq, Afghanistan, and Iran. Led by CEO Raymond Sellars, the company moves to market its tech to domestic law enforcement, but the passage of the Dreyfus Act, forbidding deployment of drones on U.S. soil, prevents this. Aware that most Americans oppose the use of military systems in their communities, Sellars asks Dr. Dennett Norton and his research team to create an alternative. The result is a proposal for a cyborg police officer. However, Norton informs Sellars that only someone who is stable enough to handle being a cyborg can be turned into one, and some candidates are rejected.
A Detroit police detective, Alex Murphy, is chosen after he is critically injured in a car bomb explosion arranged by crime boss Antoine Vallon in revenge for Murphy’s investigation into his activities. Norton persuades Murphy’s wife Clara to sign off on the procedure. Upon waking up and realizing the extent of his transformation, Murphy flies into a rage and escapes from the lab, but Norton shuts him down and brings him back to the lab. As Norton reveals to Murphy that the only remnants of his human body are most of his head (excluding parts of the brain), his respiratory organs, his heart, and his right hand, Murphy is disgusted, and asks for euthanasia. Norton reminds Murphy about his wife’s and son’s patience, and convinces him to live on. During combat training with trainer Rick Mattox, Murphy proves unable to compete with the standard OmniCorp drones in efficiency. Norton alters his programming to make him more efficient by having drone programming take over his actions, but make him think they are his. This increases his efficiency dramatically, but also makes him less empathetic due to his human nature being bypassed.
Shortly before he is to be publicly unveiled, Murphy has an emotional breakdown, forcing Norton to remove his emotions. During the ceremony, RoboCop identifies and apprehends a criminal in the crowd. He goes on to reduce crime in Detroit dramatically, simultaneously increasing public support for repealing the Dreyfus Act. Aware that Clara has begun to ask questions, Sellars orders Norton to keep her away from her husband.
Clara nevertheless manages to confront RoboCop, telling him of their son David’s nightmares. The experience leads Murphy to override his programming and access the previously sealed files on his attempted murder. From them, he learns his son was devastated after witnessing the explosion. Murphy pursues Vallon’s gang to exact revenge. He takes heavy damage from their armor-piercing weapons, but manages to kill the boss and his men. Murphy returns to the station and joins with his old partner, Jack Lewis, to confront the two corrupt cops who betrayed him to Vallon, shooting one and tazing the other. Learning that the Chief of Police was also involved, Murphy moves to arrest her, but is remotely shut down by Mattox.