The parents of Seth Rich, the DNC staffer killed in an apparent robbery in 2016, have sued Fox News over an incorrect story alleging his murder was part of a conspiracy. (Democratic National Committee/Democratic National Committee)

Sometimes a conspiracy theory can go too far.

Fox News has found out the hard way as a result of a story it published online in May and promoted avidly on the air about slain Democratic National Committee staffer Seth Rich.

The network has now been sued twice for the widely discredited story — including on Tuesday when Rich’s parents filed a lawsuit that accuses the cable network of intentionally inflicting emotional distress on them in its handling of the story.

Fox retracted the story about Rich six days after posting it on FoxNews.com but hasn’t said whether it was because the reporting was inaccurate — merely acknowledging that the story didn’t meet its “editorial standards.” The network also never issued an apology nor has it divulged whether it has disciplined any of the people involved in producing it or promoting it. That includes its “Fox & Friends” morning program and prime-time host Sean Hannity, who spent a week discussing it. The network promised to conduct an investigation last year but has not released any findings.

Like an earlier lawsuit filed in August, the latest action calls Fox’s reporting into question and could open the network to monetary damages, media and legal experts say.

Rich was a 27-year-old DNC tech staffer who was fatally shot in the District in July 2016 during what police say was a botched robbery. FoxNews.com reporter Malia Zimmerman reported — inaccurately, according to Rich’s family — that investigators had found evidence that Rich had been the source of thousands of DNC emails leaked to WikiLeaks, whose release of the documents was a blistering embarrassment for the party and its presidential nominee, Hillary Clinton. The story was never corroborated by law enforcement or other news organizations before Fox retracted it. But before it was retracted, the report was echoed on Fox News Channel shows as well as the news broadcast of WTTG, the Fox-owned station in Washington.

The story fueled an apparently baseless conspiracy narrative among right-wing websites and commentators: That Rich’s killing was payback for leaking to WikiLeaks, and that Russian sources weren’t responsible for hacking the DNC’s computers, as federal officials have said. Conspiracists have also argued that Rich’s involvement “proves” that Donald Trump’s campaign didn’t collude with Russian sources to damage Clinton.

Rich’s parents, Joel and Mary Rich, sued Fox on Tuesday, naming Zimmerman as a co-defendant, citing the stress caused by the network’s story. “The pain and anguish that comes from seeing your murdered son’s life and legacy treated as a mere political football is beyond comprehension,” the couple said in a statement.

As a practical matter, lawsuits involving intentional infliction of emotional distress can be difficult to win, said Sonja R. West, a professor at the University of Georgia law school. “Courts typically require the plaintiffs to show that the defendant’s actions were so outrageous or atrocious that they go beyond the bounds of human decency,” she said.

But it’s not unusual for such cases against the news media to go to trial, especially when they involve “overly aggressive or dishonest reporting practices,” West said. “Here, the Riches are claiming that Fox News . . . intentionally and dishonestly exploited their son’s death. And, quite obviously, grieving parents are particularly susceptible to emotional pain. So this is not a case that will be easily dismissed.”

Legal issues aside, Fox’s framing of the Rich saga “is a tragic example of running with a story that was too good to check,” said Jane Hall, a professor of journalism at American University. She called it “an egregious miscarriage of journalism.”

Fox’s lack of transparency in the aftermath of the story is particularly appalling, said Hall, a former Los Angeles Times reporter and Fox News contributor. Unlike CBS or CNN, which have fired journalists responsible for disputed stories, Fox does not appear to have held anyone to account for its Seth Rich story, she said.

A Fox spokeswoman declined to comment, citing the pending litigation.

Fox was in an unusual position on the Rich story because its reporter, Zimmerman, relied in part on one of the network’s own contributors as her only named source. Her story quoted private detective Rod Wheeler, who asserted the link between Rich and WikiLeaks. Wheeler had appeared regularly on the network to discuss law-enforcement issues.

Wheeler was investigating Rich’s killing, allegedly at the behest of Rich’s parents, and with the financial backing of Ed Butowsky, a Dallas businessman and Trump supporter. Butowsky himself has been a frequent guest on Fox News and Fox Business Network programs.

Butowsky was named as a co-defendant in the Rich family’s lawsuit.

Wheeler filed a defamation lawsuit against the network last summer, saying that Zimmerman made up quotes attributed to him in her story. He also asserted that Butowsky had discussed the Rich story with White House officials, including Trump, before it was published. Fox and Butowsky have denied those claims.

But Wheeler’s claims of mistreatment were undercut by his own actions. He went on several Fox programs in the wake of Zimmerman’s story last year, including Hannity’s, and said he had reason to believe there was a connection between Rich and WikiLeaks.

Hannity, who aggressively pushed the Rich story on his radio program, on Twitter and on his prime-time Fox program, backed off it on May 23 after Fox’s retraction. He said on the air at the time that he would stop talking about it “out of respect” for the family’s wishes. He added, however: “I promise you, I am not going to stop doing my job. To the extent to my ability, I am not going to stop trying to find the truth.”

He hasn’t mentioned Rich on Fox since then, according to a search of the Nexis database.