2029.
In Iran, mercenaries hired by OmniCorp escort a TV news crew to a compound filled with suicide bombers that is being raided by ED-209 drones created by OmniCorp. The mercenaries report to General Monroe of the United States Armed Forces in the Pentagon. He orders the ED-209 drones to move in and instructs the news crew to go live and film the raid.
The footage is aired simultaneously to an interview between General Monroe and TV personality Pat Novak (Samuel L. Jackson), which Monroe praises the ED-209 drones and OmniCorp's contract with the Pentagon. Meanwhile, in Iran, a bomber leaves his wife and his 10-year-old son hidden in a secret area of the compound and confronts an ED-209 drone, who shoots him dead before he can detonate his bomb vest. The man's son races out of the compound to help his father and is executed by the ED-209 drone as well. Monroe orders the crew to cut away.
In Detroit, police officers Alex Murphy (Joel Kinnaman) and Jack Lewis (Michael K. Williams) are pursuing mobster Antoine Vallon and his men. During the chase, another police cruiser shoots their tires, allowing Vallon and his men to escape. Though Lewis views this as an accident, Murphy is convinced Vallon has bribed the cops to help him get away.
At OmniCorp's headquarters, roboticist Dr. Robert Norton (Gary Oldman) studies the development of a chimpanzee who has received bionic implants. Norton has created a program that allows him to control the chimpanzee's body movements by intercepting and analyzing his brain patterns, manipulating the chimp into believing he's in control of his own body when he actually isn't.
In Detroit, Murphy reports the incident during Vallon's pursuit to Chief of Police Karen Dean (Marianne Jean-Baptiste). She says Murphy is a good cop, but she can't do anything unless he has proof. Returning home, Murphy meets his wife, Ellen (Abbie Cornish), and their son, David. Murphy and David play videogames together, and Ellen later comforts Murphy, telling him he's a good man.
At OmniCorp, Norton attends a meeting where the company's CEO, Raymond Sellers (Michael Keaton), is informed by his lawyer, Liz Kline (Jennifer Ehle), that footage of the ED-209 drone murdering a child was covered up, but it can't happen again, or their entire program and contracts with the government would be in jeopardy. Tom Pope (Jay Baruchel), the head of marketing, has been preassuring Sellers to bring their technology to the homefront, and Norton then suggests that they create a scapegoat that could have the blame for the programming glitches pinned on him should they happen again.
In Detroit, Murphy and Lewis learn that Vallon is hidden in a local abandoned warehouse and head there alone after reinforcements don't appear. Upon entering the warehouse, they are surprised to learn Vallon's men were waiting for them, and Lewis runs away, leaving Murphy alone. He is captured and beaten by Vallon's men, and injected with a mysterious substance. Vallon and his men then aim their guns at Murphy. Lewis hears the shotgun blasts and returns only to find Murphy's mutilated remains: a half-torso with one attached arm and the head.
In the hospital, Ellen is visited by Kline, who convinces her that OmniCorp's Project RoboCop is Murphy's only chance of survival. Ellen signs the papers transfering Murphy's custody to OmniCorp. Norton rebuilds Murphy's robotic interskeleton and wires his brain to the program that he previously used on the chimpanzee. The "prototype" is then moved to OmniCorp's Chinese division, where RoboCop 1.0 is created.
Pope conduts market research on RoboCop 1.0's appearance by asking inmates of local prisons in Detroit to rate how threatning he is. When the feedback is negative, the scientists use Pope's notes to build RoboCop 2.0, a fully functional early design. RoboCop 2.0 is trained by ex-Marine Maddox (Jackie Earle Haley) and displays his strenght, speed, agility and stamina by completing a massive obstacle race in a OmniCorp test site in record time.
Adjustments are made to the exoskeleton, leading to the creation of RoboCop 3.0, that is deployed to South Africa to disband a terrorist cell. Norton and his men monitor RoboCop's performance, and Sellers instructs Norton to force RoboCop to shoot a civilian to evaluate his emotional response. Norton confirms that Murphy feels guilt over what he perceives as his own mistake, and Sellers gives the order to "finish the product".
RoboCop 4.0 is created. He has a "Sleeper Mode", where his exoskeleton is programmed to have a blue-ish/grey-ish tint, emulating a police officer's dress blues, and a "Battle Mode", in which the plates are reinforced with bulletproof padding and become a black-tintet tactical gear for more infiltration. Throughout the process, Ellen and David request access to Murphy as they were promised by Kline, but it is continuously denied. Lewis, feeling guilty for abandoning Murphy and blaming himself for his predictment, takes up arms to help them, and, in the process, becomes a surrogate father for David.
With RoboCop completed, Norton connects Murphy's mind to OmniCorp's worldwide surveillance system, downloading records of all known registered criminals in Murphy's head. The sensorial overload of brutal crimes commited throughout the planet is too much for Murphy, and he begins to overload. Norton interrupts the process, and Sellers instructs Norton to reduce Murphy's emotions so he'll become more effective.
When RoboCop is finally reinstated to the Detroit Police Department, he is a borderline emotionless automaton under Norton's control, and initially drives his family away, resulting in Ellen becoming closer to Lewis. Murphy monitors their activities through OmniCorp's CCTV cameras, and his emotions begin to push through OmniCorp's control.
After a series of arrests as RoboCop, Murphy goes after Vallon, and learns that he was hired by Sellers to lure Murphy into a trap and mutilate him so OmniCorp could use Murphy for Project RoboCop. They had selected him as the perfect candidate, but knew he wouldn't accept by his own. Murphy also learns that OmniCorp intents to create more RoboCops, capitalizing on the popularity boost that Murphy's performance will cause among police officers.
When Murphy becomes too big a liability and Norton realizes he is beginning to resit OmniCorp's control, Sellers deploys a group of ED-209 drones to ambush and destroy RoboCop in Old Town, but RoboCop is able to outstmart and defeat them, marching towards OmniCorp's headquarters, where only one thing stands between him and the men who ruined his life: The ED-210 robotic unit, a prototype upgrade of the ED-209 design, and RoboCop's greatest challenge yet.
