Rico with the cooperation of project scientist Dr. Hayden goes against Griffin’s plans for the reactivated Janus Project by replacing the DNA samples of the original Justice Council with his own DNA, so that way a legion of perfect criminals like him will be created instead of perfect Judges like Judge Dredd. When Griffin finds out about this, he attempts to shoot the two turncoats, but Rico has his ABC warrior robot rip him apart.
Dredd, Judge Hershey, and the hacker Fergie eventually figure out that the Janus laboratory is situated inside the Statue of Liberty. They go there and encounter Rico and his cohorts, and in the ensuing battle, Fergie deactivates the ABC robot, Hershey kills Hayden, and Dredd kills Rico. The lab is destroyed in the process. The morning after, Dredd learns that the Central Computer had broadcasted all of the details of the Janus Project all over Mega City One after Griffin’s death, so everyone now knows that Rico is Hammond’s murderer, not him. He is asked by a senior Street Judge to become the new Chief Justice, but he declines, preferring to remain a Street Judge.
Rico was the one who murdered Hammond, and he is also Judge Dredd’s brother. Both he and Dredd are creations of the Janus Project, a genetic engineering project that used DNA samples from the original Justice Council in an effort to create the perfect Judge. Though Dredd became the perfect Judge that the Council had hoped for, Rico’s personality ended up getting twisted and he turned into the perfect criminal. Dredd caught Rico and had him judged for murdering civilians, but now-Chief Justice Griffin secretly had him sent to the Aspen penal colony instead of having him executed.
Griffin had been planning to reactivate the Janus Project so he could have more perfect Judges created to help him enforce a much stricter form of law and order on Mega City One, and he had kept Rico alive to help him achieve this goal. He had Rico kill Hammond because he had found out about the Janus Project, and his murder was then pinned on Dredd to get him out of the way (both because Hammond was a critic of Dredd’s, and because, since Dredd and Rico shared the same DNA, it allowed Rico to use Dredd’s Lawgiver gun). He then used Dredd’s conviction to get Fargo to step down as Chief Justice and go on his Long Walk (which he did so Dredd would get life imprisonment and not the death penalty) so that way he could ascend to the position and gain access to the Janus files. After he has Rico and his ABC warrior robot kill 108 Street Judges over the course of 48 hours, he succeeds in convincing the Justice Council to unlock the files so they can create more Judges, but when they try to back out of it, he has Rico kill them all.
However, Rico goes against Griffin’s plans by replacing the original DNA samples with his own DNA so a legion of perfect criminals will be created instead to help him take over the Mega City. Upon learning of this, Griffin tries to shoot him and the project scientist Dr. Hayden (who had decided to switch over to Rico’s side), but Rico has his ABC robot rip him apart.
Dredd, Judge Hershey, and the hacker Fergie eventually find the Janus laboratory along with Rico and his cohorts, and Dredd kills Rico after a fierce battle while Hershey kills Hayden and Fergie deactivates the ABC robot. In the process, the lab gets destroyed. The morning after, Dredd and Hershey meets a group of Street Judges, Hunters, and civilians in the street, and Dredd learns that the Central Computer broadcasted all of the details regarding the Janus Project all over the Mega City after Griffin’s demise, so his name has been cleared. One of the senior Street Judges ask Dredd to become the new Chief Justice, but he declines, preferring to remain a Street Judge, and he suits up to go back to work. Hershey kisses him, and then he leaves on a Lawmaster to cheers from the crowd.
VERY LONG VERSION:
As Judge Dredd (Sylvester Stallone) comes under attack from both the Angel Family and some Hunters while stranded in the Cursed Earth with the hacker Fergie (Rob Schneider), former Chief Justice Fargo (Max von Sydow) makes a surprise appearance and kills a Hunter before he can kill Dredd. However, Mean Machine Angel (Christopher Adamson) then mortally wounds Fargo by impaling him with his arm blade, and an enraged Dredd subsequently kills Mean Machine.
Later on, the dying Fargo reveals to Dredd that he is a result of the Janus Project. Four decades ago, the original Justice Council Fargo included put together their DNA samples and altered them enhancing the best qualities and screening out the weaknesses in an effort to create the perfect Judge. Dredd was one of the creations, and the Council created a fake photo and story about his parents so Dredd would never learn about his true origins. A shocked Dredd then finds out that Rico (Armand Assante) is also a creation of the Janus Project, which makes them brothers. He was initially a perfect Judge, too, but somewhere along the line, something went wrong with him, and he was genetically mutated into the perfect criminal. Dredd was forced to judge him for murdering civilians, and he was believed to have been executed. Dredd then realizes that Rico must still be alive, for since they shared the same DNA, it was undoubtedly him who murdered Hammond (Mitch Ryan) with the Lawgiver gun and framed him for it. Fargo initially doesn’t believe it, saying that he had signed Rico’s execution order and read the report of the execution being carried out, but then he realizes that Griffin (Jürgen Prochnow) who supplied the report must have deceived him. After begging Dredd to stop Rico, Fargo succumbs to his wound.
Griffin wanted to reactivate the Janus Project so he could create more perfect Judges with which to help him enforce a much stricter form of law and order on Mega City One. He had kept Rico alive so he could help him achieve this goal, and he had him murder Hammond because he found out about the project. He then had Dredd framed for the murder (which aside from Rico’s use of the Lawgiver was made easy by the fact that Hammond was a critic of Dredd’s) to get him out of the way, and he convinced Fargo to retire and go on his Long Walk outside of the Mega City (in exchange for a life prison sentence for Dredd) as a means of getting him removed as Chief Justice so he could ascend to the position and get the Janus files opened.
Griffin sets his plans in motion by first having Rico and his ABC warrior robot kill 108 Judges over the course of two days. Then, when the Justice Council frets over what to do about their diminished ranks, it gives Griffin the opportunity to suggest that they restart the Janus Project. The Council unlocks the files, and though they initially seem willing to restart it, given how a fully-grown adult subject could be created in just eight hours, they all end up refusing to get it going again, claiming that it is not their right to “play God.” After ordering the Central Computer to leave the Janus files unlocked, Griffin summons for Rico, who comes into the Council Room and shoots the Council dead.
Dredd and Fergie who had snuck back into the Mega City and infiltrated the Halls of Justice hear the gunfire, and Dredd blasts his way into the Council Room. Griffin orders Rico to run away, and then he shoots himself in the arm and screams to some arriving Judges that Dredd attacked him and killed the Council. Dredd and Fergie flee, and they end up taking a prototype hovering Lawmaster motorcycle and lead some Hunters in a chase across the Mega City
They successfully lose their pursuers and go to Judge Hershey’s (Diane Lane) apartment to seek her aid. Hershey confronts them shortly after they step inside, and she initially believes that Dredd has had something to do with the assassinations of the Judges, but Dredd convinces her that he is innocent. Having spent the last little while investigating Dredd’s past, Hershey shows him a photo she found of him and Rico and demands to know who Rico is. Dredd tells her all about him as well as the Janus Project.
After Fergie conducts a search of the Central Computer for the Janus Project and finds nothing, Dredd tells him and Hershey that Griffin and Rico would never take a chance and put it on the computer network, but they do need to steal power from somewhere to power the project’s laboratory, so he tells Fergie to check every sector in the city for recent blackouts and sudden power surges. Hershey then tells Dredd that, just before an assassination attempt was made against her in Sector Four, she noticed a huge power surge spanning three blocks in width, and the last time she felt something like that, the whole power grid in that area was shut down. Dredd points out that that was when the Statue of Liberty was put right down on top of the grid, and they realize that the cloning lab must be situated inside the monument. They and Fergie head there without hesitation.
Meanwhile, Griffin finds out that Rico with project scientist Dr. Hayden’s (Joan Chen) cooperation has thrown out all of the old DNA samples and replaced them with his own DNA, intending to create a legion of perfect criminals with which he can use to take over the Mega City. Angered that the duo are going against his plans, Griffin tries to shoot them, but Rico has the ABC robot seize him and then rip him apart.
Dredd, Hershey, and Fergie then enter the Statue of Liberty, but as they search for the lab, they are ambushed by the ABC robot, which shoots Fergie and grabs hold of Hershey. Rico and Hayden then appear and order Dredd inside the lab. Rico shows Dredd the first batch of clones being created and tries to convince him to join him in his bid for dominating the Mega City, but Dredd refuses to have any part of it. Rico then orders the ABC robot to come in and tells it to rip Hershey apart, but when Dredd tells him not to do it, he then orders the robot to kill Dredd instead.
Just then, Fergie jumps the robot from behind and rips out its main operating wires, deactivating it, and a battle starts between Dredd and Rico. Rico orders the Central Computer to hatch the first set of clones so he will have some backup, but because they are incomplete, they quickly prove to be of no consequence. Dredd and Rico wage a wild battle, destroying the lab in the process, and in the end, Dredd kills Rico when he throws him out of an opening in the head of the Statue of Liberty to his death on the ground below. Hayden then shows up and prepares to shoot Dredd, but Hershey kills her before she can pull the trigger.
The next morning, Dredd and Hershey followed moments later by Fergie on a stretcher go down to street level and encounter a crowd made up of Street Judges, Hunters, and civilians. Olmeyer (Balthazar Getty) tells Dredd that the Central Computer broadcasted all of the details of the Janus Project all over the Mega City following Griffin’s demise, so everyone now knows the truth and that his name has been cleared. A senior Street Judge then tells Dredd that, since the Justice Council has to be reconstituted, he and the other surviving Street Judges want him to consider becoming the new Chief Justice. Dredd declines the post, preferring to remain a Street Judge, and he suits up to head back to work. Hershey kisses him, and then he leaves on a motorcycle to cheers from the crowd.
Thanks Tornado Dragon!