D.C. Council member Jack Evans (D-Ward 2) in Washington on March 19. (Bill O'Leary/The Washington Post)

METRO HAS concluded its investigation into the actions of Jack Evans (D), the District’s Ward 2 council member who serves as board chairman. What the inquiry concluded and how it was conducted remain a mystery. Such secrecy is clearly untenable but sadly in keeping with the way the transit system often ignores its obligation to keep the public informed, thereby undermining trust in the agency.

News that the Metro board’s ethics committee had concluded its probe into Mr. Evans’s conduct came on the same day that Mr. Evans said he would not seek reelection as chairman when his term ends in June, and amid more troubling questions about whether he improperly blurred the line between elected office and his private business. Investigation by The Post’s Steve Thompson showed how Mr. Evans, the city’s longest-serving council member, acted over the years in ways that could benefit his private clients or took on clients who had benefited from his actions.

Mr. Evans has acknowledged mistakes in judgment and promised to stop all his outside work, but he denies any wrongdoing. He said his decision not to seek reelection as Metro chairman, while continuing to serve on the board, is not related to the ethical questions that have shadowed him and have made him the apparent focus of federal investigation. Metro opened its probe after The Post reported he tried to market himself to the private sector as an elected official with influence and connections.

Those actions resulted in a reprimand from the D.C. Council, but they seem to have been given a pass by the Metro board. Metro’s code of ethics bars members from using their positions for personal enrichment and cautions against conflicts of interest or the appearance of conflicts of interest. “The matter has been resolved. That’s as far as I am going to go,” Clarence C. Crawford, a board member from Maryland who headed the ethics committee, said Thursday. He refused to say whether a deal had been brokered to end the probe in exchange for Mr. Evans’s agreement not to seek reelection as chairman. “This is all internal stuff. We’re not supposed to talk about internal stuff,” said Mr. Evans.

The arrogance is mind-boggling. Public dollars fund the Washington Metropolitan Area Transit Authority, and how a public official conducts himself is the public’s business. “No one should be immune from accountability,” said Sen. Ben Cardin (D-Md.).

Metro needs to realize that it is not just Mr. Evans’s integrity that has been called into question but also that of the board. It must disclose the results of its inquiry.