'He is not well,' Scarborough responded

After addressing NBC’s firing of Matt Lauer in the wake of a sexual misconduct allegation, President Donald Trump seized on the opportunity to bring back a conspiracy theory circling MSNBC’s Joe Scarborough.

“So now that Matt Lauer is gone when will the Fake News practitioners at NBC be terminating the contract of [MSNBC President] Phil Griffin?” Trump tweeted. “And will they terminate low ratings Joe Scarborough based on the ‘unsolved mystery’ that took place in Florida years ago? Investigate!”

That “unsolved mystery” he’s referring to is the death of Lori Klausutis, a former intern for Scarborough when he was a Florida Congressman. Her body was discovered lying behind a desk in his district office in 2001. While a medical examiner stated Klausutis suffered an abnormal heart rhythm and died from a head injury sustained when she fell, some have suggested Scarborough killed her — despite the lack of evidence to suggest so.

On Tuesday, Scarborough decided that his tweets about Trump should be about “policy and not personality.” He earlier mocked the president for tweeting about his show all the time, and those two tweets have since been deleted.

In response to Trump’s latest address of the conspiracy theory, the MSNBC anchor wrote, “Looks like I picked a good day to stop responding to Trump’s bizarre tweets. He is not well.”

Trump and Scarborough have been locked in an on-going feud, with POTUS often calling his Morning Joe program and network home to be fake news.

Just the other day, Scarborough said during a segment with TIME contributor Elise Jordan, “Most of my friends now, when I call and ask them, it’s more like, ‘I’m putting up with him. He’s not Hillary Clinton. He got us a good Supreme Court justice. But God, he sure does a lot of stupid things in his tweets, and he’s just — the guy drives me crazy.’ So, they’re really getting tired of Donald Trump’s chaos and nonsense.”