With his sudden retirement Monday, former state Supreme Court Justice Seamus P. McCaffery did more than end his tenure on the high court.

He also shut down an ethics investigation with the potential to strip him of his lucrative state pension.

In exchange for his ouster, his colleagues on the court agreed to drop their order that the state Judicial Conduct Board say within 30 days whether there was evidence to bring misconduct charges against him.

That board had launched its own investigation of McCaffery even before the high court issued its order.

It has power to investigate, completely apart from what the Supreme Court wishes. And it can scrutinize former judges even after they leave office.

Yet, under the deal announced Monday, as McCaffery retreats into private life, the board is shutting down its investigation.

The deal came less than a week after federal prosecutors said they had ended a yearlong criminal investigation into referral fees that law firms paid to McCaffery's wife while she served as his top judicial aide.

But McCaffery may still face perils.

His nemesis, Chief Justice Ronald D. Castille, has said top U.S. prosecutors have told him their analysis did not preclude possible state violations.

And Castille said he met in July with Philadelphia District Attorney Seth Williams to urge him to examine the federal investigative file with an eye toward launching his own investigation.

Williams has declined to comment.

Federal judicial rules permit the sharing of grand jury information "if it shows that matter may disclose a violation of state . . . law."

The FBI in recent weeks made its interview transcripts available from its the investigation of the referral fees to the Judicial Conduct Board, according to people familiar with the matter.

About a year ago, Castille also asked Pennsylvania Attorney General Kathleen G. Kane to look into McCaffery, but there are no indications this prompted any action, perhaps because it might have conflicted with the federal probe.

Kane's spokeswoman, Renee Martin, said Monday, "We don't comment on the existence or nonexistence of any investigation in our office."

In demanding action from the Judicial Conduct Board only a week ago, the justices voted, 4-1, to urge an investigation into a sprawling array of issues:

McCaffery's participation in the exchange of 234 e-mails containing pornographic materials.

The statement from a fellow justice, J. Michael Eakin, that McCaffery had called him to say he would not be "going down alone" and suggested that Eakin too might be embarrassed by the release of X-rated e-mails.

The referral fees. In March 2013, The Inquirer reported that plaintiff law firms had paid 19 such fees to McCaffery's wife, lawyer Lise Rapaport, over the previous decade while her husband voted on cases involving some of the firms. In one case, a firm paid her $821,000 for a referral. (This firm had no appeals before the court.)

McCaffery's alleged meddling with Philadelphia civil courts. As The Inquirer has reported, sources say that McCaffery complained to a top courts administrator about a judge involved in a suit filed by a law firm that had paid a referral fee to McCaffery's wife and given McCaffery campaign donations.

The allegation that McCaffery may have fixed a $119.50 ticket given to his wife on May 14, 2010.

While the high court included the ticket allegations in its list of possible abuses to be examined by the Judicial Conduct Board, McCaffery's lawyer has said the board had looked into the matter and found no wrongdoing and given him "complete clearance."

Asked about this, the board's counsel, Robert A. Graci, said Monday, "I'm not going to be able to respond."

McCaffery's decision to leave the court came four days after he dropped a lawsuit against The Inquirer in which he alleged that the newspaper defamed him in articles about the referral fees. He withdrew his suit when the paper agreed to publish the news that federal prosecutors would not bring criminal charges in connection with the fees.

McCaffery had asked the court to block the newspaper from obtaining his financial records regarding the fees, but a judge rebuffed him. His decision to withdraw the lawsuit came as he faced deadlines to turn over the material.

His decision to step down from the high court came as the Judicial Conduct Board - at the Supreme Court's direction - was poised to delve into the fees, along with other matters.

Bruce Ledewitz, a Duquesne University law professor who is an expert on the state Supreme Court, faulted the Judicial Conduct Board for serving as an "arm of the court" and abdicating its fact-finding mission.

Lynn Marks, executive director of Pennsylvanians for Modern Courts, a judicial-reform group, said that the high court and Judicial Conduct Board had found a solution to a difficult mess.

"At the same time," she said, "I think the public deserves the opportunity to hear the truth."

The Judicial Conduct Board said that in light of McCaffery's retirement, it saw no point in digging into his actions because even if he were found guilty of misconduct, the most serious penalty he could face would be removal from office.

Graci said the state constitution mandates that the board keep its investigations secret.

"The fact that someone may have unanswered questions doesn't leave the board in a position where it can answer those questions," he said.

Under state law, judges in Pennsylvania may lose pensions for ethical transgressions, even if they are never charged with a criminal offense. The state constitution says "retirement benefits" should be stripped from a judge removed for bringing the "judicial office into disrepute."

In one example, the Court of Judicial Discipline - for which the Judicial Conduct Board serves as an investigative arm - removed Judge Ann H. Lokuta of Luzerne County for misconduct that included absenteeism and abusive behavior toward her staff.

That, in turn, prompted the state retirement system to strip Lokuta of her pension.

With his decision to step down from the court, McCaffery no longer faces such an investigation and its possible threat to his pension.

215-854-4821 @CraigRMcCoy

Inquirer staff writers Jeff Gammage and Jeremy Roebuck contributed to this article.