This article was originally published by Government Executive.

The 16-year drama of a well-known Transportation Security Administration whistleblower took another turn last month when former Air Marshal Robert MacLean was fired by the agency—for the second time.

MacLean on Tuesday confirmed to Government Executive—in the midst of higher-level drama of President Trump’s shakeup of leaders of the Homeland Security Department—that he was informed on March 21 of his termination. It came after years spent in limbo in what he viewed as make-work jobs while awaiting resolution of his complaints to the Office of Special Counsel.

MacLean’s multi-pronged case also loops in the past record of Kirstjen Nielsen, the embattled Homeland Security secretary whom President Trump fired on Sunday.

MacLean had been fired before, in 2006, after he went to the news media with disclosures that TSA might be risking air passenger safety by reducing the placement of air marshals on long flights. He took his case through the Merit Systems Protection Board and the Supreme Court, which in January 2015 ordered his reinstatement with back pay.

But on March 21, MacLean received a “notice of decision-removal,” a 20-page letter from Clyde Porter, supervising air marshal in charge of TSA’s Washington Field Office. It recapped years of the charges and rebuttals on whether MacLean posted crude, sexual and disrespectful comments on comments about other staff in a secretive online forum for federal air marshals called “Flying Pigs.” It said he had viewed a pornographic website while driving on duty (a charge MacLean denies) and that he lied about how he copied a visitors log to a TSA Dulles Airport facility to learn the names of witnesses while under investigation.

“Supervisors in your management chain have questioned your judgment and reliability, and characterized your actions as negatively impacting the work environment,” Porter wrote.

In an interview with Government Executive, MacLean, now unemployed, characterized the events as part of a long-term retaliation against him by managers. “The baseline is that I begged for a transfer as soon as the Supreme Court appeal was decided. “I didn’t want to go back to TSA,” he noted, saying he would have preferred to return to his previous job at Border Patrol. “They flat-out rejected my proposal, for no reason, with no counterproposal.”

TSA spokesman Thomas Kelly on Tuesday told Government Executive, “While TSA cannot comment on specific personnel actions, TSA treats all employees in a fair and lawful manner, and does not engage in retaliation of any kind.”

MacLean’s attorney, Tom Devine of the Government Accountability Project, said “the agency has been trying to fire Mr. MacLean from the day he was reinstated. They wanted to defeat the whistleblower who defeated them in the Supreme Court.”

Devine ranks MacLean among one of the nation’s top whistleblowers. “This is a case where an agency has relentlessly, crudely defied the Whistleblower Protection Act,” Devine wrote to the Office of Special Counsel. “It will be a weathervane whether even a Supreme Court victory can save a whistleblower’s career. It deserves decisive action by the Special Counsel.”

Devine has pressed for OSC intervention. In a long April 1 letter to Special Counsel Henry Kerner, he said, “Mr. MacLean has made more of a difference correcting aviation security breakdowns than any other employee in agency history. His 2003 disclosures may have prevented a more ambitious rerun of the 9/11 tragedy. Immediately upon his reinstatement and steadily since, Mr. MacLean has made substantive disclosures forcing review and corrective action on security lapses.” Devine cited MacLean’s design of a new aircraft cockpit barrier, which he offered to TSA but has not patented.

MacLean said he suspects the timing of the firing was based on the fact that the Merit Systems Protection Board lacks a quorum and hence is inactive. “They waited 10 months” from the June 8, 2018, letter of proposed termination with OSC talks ongoing. “They figured the MSPB would be rendered impotent, unable to issue a stay requested by the OSC, which is 100 percent on my side,” MacLean said. (Asked for comment, the OSC could only confirm receipt of the letter.)

He said he also believes TSA was “extremely upset about uploading their November 2009 ‘TSA HEROISM AWARDS’ document I found buried in the TSA iShare intranet database,” which provided details about the agency’s alleged misrepresentation of a witnessed rape of a woman in the restroom at Reagan National Airport just before the inauguration of President Obama.

Deep inside MacLean’s lengthy documents and testimony to investigators are at least two notable items, he said. In a Nov. 5, 2018 affidavit, he apologized for having castigated then-TSA Administrator Peter Neffenger by telling Government Executive that the admiral was in cahoots with managers determined to retaliate. (He said he later learned that Neffenger was kept in the dark.).

And he made the point that Nielsen was involved as early as 2003. At that time, she was head of congressional relations for TSA. “DHS Secretary Nielsen was deeply involved with my July 2003 disclosures that outraged bipartisan/bicameral members and leaders in Congress,” MacLean wrote last year. A July 30, 2003, online Fox News article titled, “DHS: No Plan to Cut Number of Air Marshals,” proves that the agency—through Ms. Nielsen, who was in charge of the agency’s congressional affairs—was feeding Congress patently false information.”

Nielsen, MacLean said Tuesday, had her “office blown up” by all the complaints from lawmakers. “I don’t think anybody had more headaches than her.”