SUDDENLY SPORTING a cane, a new medical diagnosis and an air of contrition, former Prince George’s County executive Jack B. Johnson finally faced judgment Tuesday. After eight years of corruptly running Maryland’s second-largest locality for his private enrichment, and after months more of denials and arrogance following his arrest, Mr. Johnson at last got around to apologizing, asking “the people of Prince George’s to forgive me.”

It was too little, and much too late. U.S. District Judge Peter J. Messitte, disregarding Mr. Johnson’s abrupt claims of infirmity but giving him some credit for cooperating with prosecutors, handed down a sentence of more than seven years in federal prison, plus a $100,000 fine. The judge correctly described Mr. Johnson’s career arc as “a deliberate march down a long path of kleptocracy.”

Those plain words should be long remembered in Prince George’s as a corrective against whatever residual sympathy may remain for Mr. Johnson. The insidiously cynical views of Mr. Johnson’s case — that his only mistake was getting caught; that all he did was help his friends; that he was no worse than others; or that he was targeted because he is an African American — should be dispelled now that he has been unmasked as a crook.

Even at this late stage, Mr. Johnson, 62, was willing to play the angles. He described himself during his sentencing hearing as “a very ill man” with Parkinson’s disease. Prosecutors countered that medical reports found only that he might have the disease — and that the FBI had photographed him playing 18 holes of golf, hoisting his own bag of clubs, a week after his “diagnosis.”

Mr. Johnson, who pleaded guilty to extortion and tampering with witnesses and evidence, took hundreds of thousands of dollars in bribes by shaking down developers. His graft and chicanery began practically from his first days as Prince George’s top local elected official and extended nearly to his last. Even now, 13 months after his arrest, prosecutors and county officials continue trying to unravel Mr. Johnson’s various schemes to enrich himself, and to determine whom he may have tainted or drawn into his web along the way.

Mr. Johnson once mused, in a conversation recorded by the FBI, that prosecutors, supposedly intent on pursuing minorities, would love to brag that they’d brought him down. He noted that he had to be careful — and in the same breath he pocketed a $1,500 bribe, one of many such payoffs.

He fancied himself a potential victim. The truth is that he was a victimizer; the real victim was Prince George’s County. A swindler posing as a public servant, he grabbed all he could for as long as he could, confidently supposing that no one — not the press, not the public, and not prosecutors — would ever catch up with him or figure it all out.