In 2016, public radio station manager J.J. Yore made repeated attempts to get rid of an employee he suspected was a serial sexual harasser. But the administrators he answered to recommended warnings and reprimands instead.

It wasn’t until late 2017 that anything changed.

As the #MeToo movement galvanized workplaces across the country on the issue of harassment, Yore redoubled his efforts to address a situation he feared could turn into a scandal at Washington’s WAMU-FM — and uncovered a troubling track record of past behavior at the employee’s previous job, according to several people familiar with the sequence of events and emails detailing what occurred.

Those were the efforts that appear to have finally led to the resignation of WAMU reporter Martin Di Caro. Yet his protracted tenure left ill will in the newsroom, where many were aware of questions about his behavior but not about management’s confidential efforts to deal with it. Those tensions spilled into public view this summer amid broader complaints about Yore’s management of minority employees — prompting a near-revolt by station staff that ended in Yore’s resignation.

The Di Caro case shows how layers of bureaucracy and the confidentiality that shrouds personnel matters affect attempts to address harassment complaints. Internal emails and interviews about the matter also offer new insight into the fraught newsroom dynamics that led to Yore’s downfall from one of the most prestigious jobs in public radio.

WAMU insiders spoke for this story on the condition of anonymity to discuss sensitive personnel decisions. A story first published late Wednesday by DCist also detailed American University’s role in overruling station managers in dealing with the harassment complaints.

A co-creator of the popular show “Marketplace,” Yore was a rising star within public radio in 2014 when he took over as general manager of WAMU, an NPR affiliate and home of the then-widely syndicated “Diane Rehm Show.” During his time there, revenue nearly doubled and the roster of regular donors shot up nearly 60 percent. The station also doubled its news and production staff at a time when other local news organizations were cutting back.

Di Caro, who had joined WAMU as a part-time reporter two years before Yore’s arrival, doggedly covered the local transportation beat. He also allegedly had problematic personal relationships: In late July, the news site DCist, owned by WAMU, documented complaints from more than 20 people who said he had subjected them to inappropriate and unwelcome comments during his five years at the station. When Di Caro resigned, he told colleagues he wanted to take a break from reporting; there was no public indication that his departure was related to harassment.

The DCist article was the catalyst for a tumultuous staff meeting, during which employees poured out complaints about Yore’s management of minority employees as well as demanding to know why Yore had tolerated Di Caro for so long. Yore, who quit several days later, said at the time that he was prevented from explaining his actions because of confidentiality restraints on personnel decisions.

Left unanswered at that meeting were questions about the university’s oversight of the matter. Interviews and emails indicated that university administrators were involved with investigating the three accusations against Di Caro, between 2014 and 2016. The administrators — Deadre Johnson, American’s senior director of employee relations; Beth Muha, assistant vice president of human resources; and then-assistant general counsel Hisham Khalid — concluded each time that there were insufficient grounds to dismiss Di Caro. On two occasions, they directed Yore to issue formal warnings to Di Caro that he could be fired if he committed another infraction, emails and interviews with Yore’s colleagues indicate.

With the second two accusations, both in 2016, Yore and WAMU’s chief news and programming manager, Andi McDaniel, pressed for Di Caro’s dismissal. An email that Yore sent to newsroom managers in May 2016 to discuss filling a vacancy on the transportation beat indicates that it was his intention to fire Di Caro, an action he seemed to assume would be completed in a matter of days.

“Regarding Martin: I think it will take us all week to come to final terms. . . .” Yore wrote on May 16. “I’d like to push with the HR and legal folks on being as clear as we can that Martin did some things that required us to terminate him. Language along the lines of, ‘Martin Di Caro has engaged in a pattern of activity that threatens the integrity and reputation of WAMU and American University. As a result, Martin is no longer employed by WAMU/AU.’”

But an email sent by Johnson to the station’s managers a week later indicated that the university’s legal office advised that Di Caro receive a “final written warning” for what administrations deemed a “Level 3 violation of serious misconduct.” Johnson wrote: “The thought here is let Martin know that we ‘considered’ terminating his employment so that he understands the seriousness of the situation.”

American University’s chief spokesman, Matt Bennett, speaking on behalf of the university and the administrators, declined to address specific questions about Di Caro and Yore. But he suggested that it had been Yore’s responsibility, in what he described as a “consultative process,” to persuade his bosses that firing Di Caro was the appropriate remedy. “While this is a collaborative process, the supervisor has authority to determine the disciplinary action most suitable to the situation, as outlined in the American University Staff Personnel Policy Manual,” he said.

Yore has repeatedly declined to offer comment, saying last month in an email that the university’s lawyers “have made it clear” that he is prohibited from doing so. WAMU and Di Caro signed a separation agreement upon his departure that prohibits both parties from discussing his work history. (“I recognize and regret that this means aspects of this story will remain unchallenged and incomplete,” Yore told DCist before his resignation.)

McDaniel, who left WAMU in June, noted that WAMU did not have its own human resources or legal departments and had to rely on American’s, which kept station management from being able “to issue the penalty we saw as most appropriate.” While noting she couldn’t speak to the specifics of Di Caro’s case, she said in an email to The Washington Post: “I am incredibly frustrated to be left to defend decisions I actively fought against, and in which I did not have decision-making authority.”

McDaniel’s account is corroborated by Steve Swenson, a public-radio-station executive who employed Di Caro in New York 15 years ago. He spoke to Yore about Di Caro in late 2017, and Yore “expressed to me that people in HR had told him they didn’t have enough to do anything” about Di Caro, said Swenson, who is now with a station in Nashville. “It was clear to me that J.J. was frustrated and was unable to get [Di Caro] to leave.”

The three complaints against Di Caro were filed between 2014, shortly after Yore’s arrival at the station, and 2016, according to multiple insiders who detailed them for The Post. The first, from a staffer for the Washington Metropolitan Area Transit Authority who said he made several inappropriate comments to her, resulted in a “Level III” warning from the university — essentially putting him on notice that he could be fired after another infraction — and a requirement he take an online sexual-harassment education course. A second, in January 2016, from a female reporter for a local newspaper who declined to participate in a follow-up investigation, was resolved when Deadre Johnson, the university’s senior employee relations director, gave Di Caro an informal warning. So when another female journalist complained about Di Caro in May 2016, WAMU managers were stunned when university officials issued another “Level III” warning, again sparing him from termination.

Some weeks later, McDaniel privately expressed her frustrations to Alicia Montgomery, who joined WAMU as news director in the fall of 2016. “It was absolutely clear Andi wasn’t happy,” Montgomery told The Post. “The spirit of the conversation was, ‘How are we going to handle this?’ ” She said that McDaniel indicated to her that if Di Caro misbehaved in the newsroom, they should take the opportunity to again seek his dismissal.

Montgomery, who left the station in 2017, argues that management had that opportunity several weeks later, when Di Caro berated a woman in the newsroom. But she says that when she reminded Yore of the Level III warning hanging over Di Caro’s head, Yore was concerned other staffers would wrongly perceive that the reporter was being fired just for yelling at a colleague. After that, Montgomery says, she moved from her office to a desk in the middle of the newsroom, primarily to keep an eye on Di Caro.

Di Caro responded to a request for comment by stating that “American University always treated me fairly, abiding by due process” and that “I deeply regret having made people feel uncomfortable in a professional setting.” He added: “How much longer must we re-litigate things that were resolved years ago?”

Di Caro’s profile and responsibilities grew during his time at WAMU. He began as a part-time employee in 2012, but was made full-time in 2015, as the station pushed to limit its reliance on a part-time workforce. In April 2016, he was promoted to “senior” reporter and given a raise, reflecting both his work and a newsroom-wide effort to upgrade salaries. A month later, the station named him the host of a podcast about local transportation matters.

Di Caro continued to work at the station after receiving his second formal warning for another 18 months. But in October 2017, sexual harassment complaints against prominent men sparked the ­#MeToo movement, and Yore became concerned that WAMU could face its own scandal, according to people inside and outside WAMU who spoke with him at the time. His fears were heightened by the resignation of NPR’s top news executive, Michael Oreskes, who was accused of misconduct by two women.

After Yore mentioned the issue to subordinates, a WAMU manager who had been unaware of the local complaints against Di Caro volunteered that the reporter had similar issues when they both worked at WCBS in New York, according to station insiders. McDaniel confronted Di Caro with this information and got permission to obtain his personnel records from WCBS. And Yore spoke to Swenson, Di Caro’s former boss there, who says he confirmed that Di Caro had been the subject of complaints around 2004. In one case, a woman got a restraining order requiring him to keep his distance from her, according to documents viewed by The Post. (Di Caro declined to comment on this.) Swenson said WCBS severed ties with Di Caro, then a freelancer, around 2005, on the advice of its corporate human resources department.

Yore presented the information to American University officials — and this time, they agreed that Di Caro should be terminated, according to emails and interviews. Faced with being fired, Di Caro resigned in late 2017 instead. The circumstances of his departure were kept confidential, though, and five months later, he joined Bloomberg Radio. Bloomberg briefly suspended him in late July after news broke of his alleged misconduct at WAMU. The company later reinstated him, saying it found no infractions during his time there. As of this week, though, Di Caro is no longer working for Bloomberg, according to a person familiar with the situation.

WAMU has since instituted reference and criminal-record checks on all potential hires — a policy that was not in place for part-time employees when Di Caro joined as a part-timer, people familiar with its hiring practices say.

Given the damaging publicity surrounding the Di Caro matter, Yore’s future in public radio seems cloudy at best, and he has made no announcement of future career plans. Meanwhile, McDaniel, his former deputy, lost a new job amid the fallout: In May, she was hired as chief executive at Chicago Public Media, but after the Di Caro news broke in late July, its board launched an investigation, and last week, she withdrew under pressure, leaving her jobless a few weeks before her official starting date. In a statement, the organization’s board said it made the decision after “deeper research into the recent turmoil at Andi’s prior employer, WAMU.”