Donald Trump Jr joins dad's feud against Morning Joe hosts as president continues hurling murder accusations

Donald Trump Jr. joined his father's feud against MSNBC's co-hosts Joe Scarborough and Mika Brzezinski.

The president again accused the "Morning Joe" host of murdering a former congressional staffer who died on the job in 2001, and Brzezinski fired back on the show and on Twitter.

“He’s once again tweeting conspiracy theories about Joe, falsely accusing him of murder, talking about a death of a young staffer in his office years ago, and calling him dangerous to walk the streets,” said Brzezinski, who married Scarborough in 2018. “That’s sick, Donald -- you are a sick person."

Trump has been calling for a cold case investigation of the staffer's death, which a coroner found was linked to an undiagnosed heart condition that caused Lori Klausustis to pass out and hit her head.

The president's eldest son then mocked Brzezinski by calling her "Karen," which has become a derogatory term for women who angrily demand to speak to store managers to complain about minor injustices.