The Crime Doctor originally got his kicks by committing crime but did not enjoy the profits of his criminal acts, which he later donated anonymously to charity. Early in his career, the Crime Doctor realised that Bruce Wayne was Batman when as the Crime Doctor recognised injuries that he had treated Bruce Wayne for. Somehow, word got out that Crime Doctor knew Batman's secret identity. and the crimelord Sterling Siversmith attempted to pry the information from Thorne. When Thorne refused to reveal Batman's true identity, Silversmith injected quicksilver into Thorne's bloodstream to force him to talk, but still Dr. Thorne refused to talk. Batman, unable to reach Thorne in time,found the Crime Doctor a complete vegetable.
During the Crisis, Crime Doctor was one of the super-villains who banded together to take advantage of the chaos. He was apparently cured of his mental disability, a fact confirmed by his next appearance on the scene, when it became apparent that he was now completely malevolent. Whether Thorne retained his knowledge of Batman's identity is unknown. He currently works with the Society, where he inflicts great pain on traitors and other enemies.