Former President Donald Trump was privately “raging” over media coverage of his historic arraignment in Washington, DC Thursday, where he pleaded not guilty to four counts in federal court—the charges related to Trump’s efforts to overturn the results of the 2020 presidential election, leading up to the January 6, 2021 attack on the U.S. Capitol.

On CNN News Central Friday, reporter Alayna Treene, citing sources, described Trump as “very angry” after his arraignment—in part because the judge referred to him as “Mr. Trump” and not “Mr. President.” Later, Trump was “raging on the plane” as he flew from Washington to his home in Bedminster, New Jersey. “He was definitely pissed off,” Treene said, “as he was watching the enws coverage of this come in. And so even though publicly he still wants to sound defiant...privately he is very angry.”

After leaving the courthouse Thursday, Trump spoke to reporters at Ronald Reagan Washington National Airport, saying his most recent indictment was “persecution of a political opponent” and calling it “a very sad day for America.”

On Friday afternoon, Trump took to his Truth Social platform to again accuse President Biden of using the Justice Department to target a political rival. “Every one of these many Fake Charges filed against me by the Corrupt Biden DOJ could have been filed 2.5 years ago, but they waited and waited until I became dominant in the Polls, and then they filed them all, including locals, right in the middle of my Campaign,” he said. “They want anybody but “TRUMP.” Not fair and perhaps, not legal. ELECTION INTERFERENCE!!!”

During its coverage of Trump’s court appearance Thursday, ABC News senior investigative reporter Aaron Katersky described a moment in court when Trump looked right at special prosecutor Jack Smith, describing it as “a moment that clearly shows how, perhaps, angry the former president is with this particular indictment.”