Karl Raider was a vigilante ex-Judge who lived in City Bottom.
Raider graduated from the Academy of Law as a Judge in 2079, the same graduating class as Joe and Rico Dredd. He was the only Judge that year to even come close to equalling the clone brothers on marksmanship.
In 2099, Raider fell in love with a citizen named Carol. He decided to leave the Justice Department and become a citizen. During the Apocalypse War [1], Carol became infected with radiation and Raider decided to end her life to spare her pain.
By 2114, Raider was now a vigilante dealing out his own version of justice to criminals in City Bottom. After attacking Murk Derryson's mob, Raider comes to the attention of Judge Dredd. Raider is killed by Dredd [2].