A City Hall legal drama years in the making drew to a quiet close Wednesday as a federal judge accepted prosecutors' decision to dismiss their public corruption case against a top aide and two supporters of former Philadelphia City Councilman Jack Kelly.

U.S. District Judge Eduardo Robreno had scheduled a new trial to begin for Kelly's former chief of staff, Christopher Wright; lawyer Andrew Teitelman; and developer Ravinder Chawla in August.

But earlier this week, prosecutors moved to withdraw the case, citing "new witness-related developments due to the passage of time which lead the government to believe it can no longer prove its case beyond a reasonable doubt."

Wright's lawyer, Lisa Mathewson, said she did not know what "witness-related developments" prosecutors were citing but said she welcomed the judge's decision.

"The right decision is always welcome even when delayed," she said. "We've always viewed this as a case in which the government could not prove bribery because no bribery took place."

Before his indictment in 2008, Wright was a fixture at City Hall, having worked for Councilman W. Thacher Longstreth before becoming Kelly's chief of staff. It was in that role, prosecutors alleged, that he accepted a rent-free apartment from Chawla, one of Kelly's largest campaign contributors, and free legal services from Teitelman, Chawla's lawyer and Kelly's campaign treasurer, in exchange for his influence in city government.

A jury convicted the three men in 2009 in a trial before Robreno, and all served short stints in prison. But the legal twists and turns their case took afterward left them on the hook for far longer than their original sentences would have kept them behind bars.

Wright was sentenced to four years in prison, while Chawla got 30 months and Teitelman two years.

In January 2012, however, the U.S. Court of Appeals for the Third Circuit tossed their original conviction and ordered new trials for the men. Though the panel upheld the evidence used to convict the men at the time of their first trials, it said a 2010 U.S. Supreme Court ruling in an appeal by former Enron executive Jeffrey Skilling changed the scope of the law under which they were charged.

In that case, the high court said that an apparent conflict of interest was no longer enough to convict officials charged with fraud for depriving the public of "honest services" and that in the future prosecutors must be able to prove actual bribes were exchanged.

In a 2013 hearing, U.S. Attorney Zane David Memeger told Robreno that the Skilling ruling had "created a mess for federal prosecutors." The case against Wright was just one of the casualties.

Prosecutors sought to avert a new trial by striking a plea agreement with Wright, Chawla, and Teitelman to misdemeanor fraud charges. But Robreno rejected their deal later that year, saying he was unwilling to hand government lawyers "a fig leaf" to let them obscure a crime or a flawed prosecution.

If the office planned to dismiss the case, the judge said at the time, "it should do so openly and transparently - and tell the people of Philadelphia why, after having trumpeted for years this case as a public corruption case, it is no longer so - and why the conduct involved here does not warrant further prosecution."

On Wednesday, First Assistant U.S. Attorney Louis Lappen offered that explanation:

"We considered all of the facts and circumstances of this case, including the U.S. Supreme Court's decision in Skilling and recent developments with witnesses," he said, "and concluded that it did not serve the interests of justice to proceed with this prosecution."