Federal prosecutors in Chicago on Wednesday indicted a longtime top aide to ex-Illinois House Speaker Michael Madigan on charges of perjury and obstruction of justice, intensifying a corruption probe into the former top House Democrat.

The new criminal charges against Tim Mapes, Madigan’s one-time chief of staff and the former Democratic Party of Illinois executive director, allege that he misled a federal grand jury multiple times last March.

Mapes’ testimony was focused, in part, on indicted former Commonwealth Edison lobbyist Michael McClain, a close friend of the ex-speaker’s, and the role McClain played as an intermediary and advisor for the top House Democrat in 2017, 2018 and 2019.

Commonwealth Edison has acknowledged in federal court papers that it engaged in a long-running bribery scheme aimed at currying favor with Madigan to advance the utility’s agenda in Springfield for nearly a decade.

The company acknowledged it provided jobs, contracts and payments to members of Madigan’s political organization and other associates of the speaker, with McClain acting as a conduit with Madigan, who has not been charged.

Mapes, who had immunity from prosecution at the time of the interview, allegedly told investigators repeatedly he was unaware of McClain’s interactions with Madigan, a claim federal prosecutors contend was false based on email and telephone calls during those years.

In one bit of grand jury testimony prosecutors divulged, Mapes was asked about McClain and Madigan’s interactions between 2017 and 2019.

“Do you recall anyone ever describing any work or assignments [McClain] was performing on [Madigan’s] behalf?” a prosecutor asked.

“I don’t recall that – that I would have been part of any of that dialogue,” Mapes answered. “I don’t know why I would be.”

“The answer is yes or no to that question. Do you recall?” the prosecutor responded.

“No, I don’t recall any of that,” Mapes said.

Mapes’ defense lawyer, Andrew Porter, denied the allegations against his client and said the indictments are a reflection of government efforts to indict Madigan, who lost his speakership in January over allegations surrounding the federal probe. Madigan has not been charged and denies wrongdoing.

“Tim Mapes testified truthfully in the grand jury,” Porter said. “His honest recollections – in response to vague and imprecise questions about events that allegedly took place many years ago – simply do not constitute perjury.

“This case, of course, is not about him – but about the government’s continued pursuit of his former boss,” Porter continued. “Tim Mapes has, in no way, engaged in obstruction of justice, and looks forward to prevailing at trial when all of the facts are aired.”

The indictment went on to allege that Mapes lied to the grand jury about his knowledge of conversations McClain had in 2018 with two members of the House Democratic caucus, identified only as Public Official B and Public Official C.

The indictment alleges McClain told Mapes about the discussions but doesn’t detail their substance nor allege wrongdoing by those officeholders. WBEZ has confirmed those public officials to be state Rep. Bob Rita, D-Blue Island, and former state Rep. Lou Lang, D-Skokie.

“We have no idea who or what they’re talking about in this,” Rita told WBEZ in a statement Wednesday night. Rita did not respond to a question about whether he’d been asked to testify before a grand jury.

Lang did not respond to a message from WBEZ.

The indictment also says Mapes lied to the grand jury about whether he had any knowledge of Madigan’s “impressions” of a ComEd executive identified as Individual C. WBEZ has confirmed the identity of that individual as company CEO Joseph Dominguez, who succeeded Anne Pramaggiore in that role in 2018.

Pramaggiore, who moved to an executive role with Exelon Utilities, is facing criminal charges tied to the ComEd probe. She was indicted last November along with McClain and two others.

Dominguez, a former federal prosecutor, has not been implicated in any wrongdoing.

The Mapes indictment is certain to create major ripples in the closing days of the Springfield legislative session, where ComEd and its corporate parent, Exelon, are trying to negotiate a new energy bill before a scheduled Monday adjournment that could include subsidies to keep its nuclear power plant fleet afloat.

“Today’s indictment of former chief of staff Tim Mapes underscores the criminal enterprise operated under the dome by former Speaker Michael Madigan, also known as Public Official A,” said House Minority Leader Jim Durkin, R-Western Springs.

And the state Republican Party was quick in trying to make money off the Mapes indictment by sending out a fundraising pitch to potential donors that alleged, without proof, that Madigan’s indictment is imminent.

“There is no better time than NOW to capitalize on the exposing of the Illinois Democrat Crime Ring,” the pitch went. “We need you.”

Mapes was forced out of Madigan’s inner circle in 2018 after he was accused of bullying an employee and improperly handling her complaints of harassment.

State records show Mapes, 66, of Springfield, is now drawing a $141,306 annual pension.

In November, Lausch’s office indicted McClain for his role in the ComEd bribery scheme. He enjoyed a unique, dual role as both top lobbyist for ComEd and unofficial political adviser to Madigan. The two men served in the state House together decades ago, but after McClain lost his seat in western Illinois – despite big support from Madigan – he continued to be one of the most trusted members in the inner circle of the famously coy speaker.

McClain told WBEZ early last year that federal agents had tried to convince him to cooperate, and he implied at the time that he was not inclined to do so.

McClain has pleaded not guilty to the charges. His lawyer, Patrick Cotter, has alleged that federal prosecutors here were conducting a “misguided investigation and misapplication of the law, driven by an obvious desire to find some way to criminally implicate a current elected official, who happens to be Mike McClain’s longtime friend.”

“The goal of these meritless charges is clear: to apply maximum pressure on Mike McClain, and others, to help the Government in its efforts against his friend,” Cotter said, in a clear reference to Madigan. “But Mike McClain cannot agree to allegations that are untrue, even to escape the crippling weight of the Government’s attacks.”

Dave McKinney and Tony Arnold cover Illinois politics and government for WBEZ. Follow them on Twitter @davemckinney and @tonyjarnold.