Judd was originally a Judge, Head of Genetics at the Justice Department, and a prominent member of the Council of Five. He had been the one to propose the idea of cloning Judges and began this program under Chief Judge Goodman - the most notable success had been Judge Joe Dredd, who had been cloned from the DNA of Chief Judge Fargo. He was heavily disliked by Judge Solomon for his amorality.
After the Atomic Wars of 2070, Mega-City One was left in turmoil. As a result, Judd proposed a radical solution to the problem of policing an overcrowded city, packed with 400 million potential criminals. The solution was to clone the citizens, as well as the Judges, to create a docile and obedient population. Although he had some support amongst many of his colleagues, Chief Judge Fargo rejected the idea, pointing out that the Judges' first duty was to serve the citizens, not to control them.
After a failed attempt to assassinate Fargo, Judd and a number of his followers were scheduled for execution. However, they were rescued at the last moment and fled Mega-City One with a batch of genetic material.
Judd could not be found and was presumed dead until he reappeared almost forty years later. Judd and his followers had built a secret base inside the caves of Ayers Rock in the Radback (radioactive outback) of Australia, breeding their own army of 'Judges' called the Judda from the DNA stock he had stolen from the Justice Department. His plan was to despatch a group of them via sophisticated teleportation devices to Mega-City One in order to kill several key Judges, preliminary to his conquest of the city he regarded as rightfully his. This failed when Judge Dredd captured one of the group and used his teleportation device to return to Judd's base. Judd panicked and tried to accelerate his mass assault on the Grand Hall of Justice, but Dredd used Judd's device to get back there first. Forewarned, the Judges were ready for the onslaught and Dredd teleported an armed nuclear warhead back to Ayers Rock, destroying Judd and the remainder of his followers.
- One survivor of the Judda attack was Kraken, one of Fargo's clones, who was taken prisoner and re-indoctrinated to become a judge, with a view to one day becoming Judge Dredd's replacement. Kraken became a major character in the Necropolis storyline.
- The Judge Dredd Yearbook 1993 story Parallel Lines had a parallel universe, Dimension Parallel 717, where Morton Judd had never been exiled. The planet was ruled by the Justice Lords of Judda-City One, who execute people for even thinking of a crime and had been invading parallel universes.
- The audio drama Judge Dredd: Jihad, written by James Swallow and published by Big Finish Productions, featured two last remaining Judda, a clone of Dredd named Jonah and his sister, Pandora, leading a fanatical Judda cult. According to these two, Dredd infiltrated the Judda, claiming to follow Judd's beliefs, then cowardly shot Judd in the back before escaping and bombing the Judda's base, for which he is regarded by the surviving Judda as "the Devil." Jonah tried to take over Mega-City One with the threat of a nanotechnology weapon, but was foiled by Dredd. Judd appears briefly in flashback, voiced by Garrick Hagon, who also voices Jonah.