For a while, he has been pushing this Seth Rich murder conspiracy theory. The story claims that Seth was DNC mole passing info to Wikileaks and later killed for it. The story had several holes in it, but that didn't stop Hannity. He kept the story going, until Fox News jumped in.
They released this statement
On May 16, a story was posted on the Fox News website on the investigation into the 2016 murder of DNC Staffer Seth Rich. The article was not initially subjected to the high degree of editorial scrutiny we require for all our reporting. Upon appropriate review, the article was found not to meet those standards and has since been removed.Later, Seth Rich’s parents wrote an op-ed, begging Fox News to stop politicizing Rich’s murder. With more added pressure from fellow Fox News staffers and the public, Sean caved
We will continue to investigate this story and will provide updates as warranted.