EAST PROVIDENCE, R.I. – Never mind that former Providence Mayor Vincent “Buddy” Cianci spent more than four years in prison on a federal corruption conviction. Forget that prosecutors painted his administration as rife with bribery and graft.

The past is swept aside on weekday afternoons, when Cianci uses his popular radio talk show to accuse local officials of wrongdoing and bad judgment, revel in their stumbles and hammer ceaselessly at those who cross him.

Though convicted of abusing the public trust, Cianci now postures himself as a good-government watchdog — an irony readily apparent to his critics.

“Buddy is the epitome of a self-promoter, and he uses the radio and television for self-promotion,” said Lincoln Almond, a former Rhode Island governor and U.S. attorney. “He will always say what he thinks is going to help him at anyone’s expense.”

But Cianci — who, as the longest-serving mayor in Providence history, maintains a devoted following — sees no hypocrisy.

He argues he’s already served his time, was acquitted of all but one count (racketeering conspiracy) and never improperly took a dime.

Cianci relies on a network of tipsters — often disgruntled city employees — plus institutional knowledge gleaned from more than 21 years as mayor to deliver news he believes listeners wouldn’t get elsewhere.

“People call me. We expose a lot of stories here, whether it’s the police department, whether it’s state stuff,” he boasted between guests on a recent show.

Then, he deadpanned, “I know where the bodies are buried.”

Cianci, 69, landed his show on WPRO-AM soon after his release from prison in 2007, reprising a role as talk-show host he held between his first and second stints as mayor.

He now occupies the coveted evening-drive time slot, where his attacks on his favorite punching bag, Providence Mayor David Cicilline, will likely amplify as Cicilline runs for Congress this year.

Cianci’s insight and witty banter make him a logical fit for radio, even if his history makes him a questionable messenger, said Rhode Island political analyst Marc Genest.

“You have the good Buddy, who is this insightful political analyst and does a remarkable job of critiquing policy,” Genest said. “And then you have the bad Buddy, who’s willing to chop off your feet if you get out of line.”

It’s hard to tell how much Cianci’s attacks sway public opinion, but his opponents may feel compelled to respond if enough people start repeating the criticism, Genest said.

Though Cianci spends ample air time complaining about the current administration, he also has broken news.

In the fall, he revealed how a handcuffed, breaking-and-entering suspect had been beaten by a Providence police officer in a parking lot — an assault caught on video by a nearby building’s security camera. Prosecutors convened a grand jury, and a detective was indicted in February on a felony assault charge.

This month, Cianci conducted the first extensive interview of the beating victim, interspersing sympathetic questions with attacks on the police department — the same force tarnished under Cianci’s administration by a scandal over cheating on a promotional exam.

“Where are our U.S. senators? Where’s our congressmen? Why aren’t they calling the Justice Department to get involved in this?” Cianci thundered. “I mean, come on, this is crazy.”

He’s also a commentator on Rhode Island’s ABC television affiliate, where last month he got North Providence Mayor Charles Lombardi to allege on-air that he had been the target of a shakedown attempt over a municipal judgeship appointment.

“I’ve been there. You’ve been there too,” Cianci said. “It happens.”