Prosecutors working for Jack Smith, the special counsel who has twice brought indictments against former President Donald J. Trump, obtained a search warrant early this year for Mr. Trump’s long-dormant Twitter account as part of their inquiry into his attempt to overturn the 2020 election, according to court papers unsealed on Wednesday.
The warrant, which was signed by a federal judge in Washington in January after Elon Musk took over Twitter, which is now called X, is the first known example of the prosecutors directly searching Mr. Trump’s communications and adds a new dimension to the scope of the special counsel’s efforts to investigate the former president.
The court papers, which emerged from an appeal by Twitter challenging the judge’s decision to issue the warrant, did not reveal what prosecutors were looking for in Mr. Trump’s Twitter account, which the tech company shut down just days after the attack on the Capitol on Jan. 6, 2021.
But the papers indicate that prosecutors got permission from the judge not to tell Mr. Trump for months that they had obtained the warrant for his account. The prosecutors feared that if Mr. Trump learned about the warrant, it “would seriously jeopardize the ongoing investigation” by giving him “an opportunity to destroy evidence, change patterns of behavior, [or] notify confederates,” the papers said.
The existence of the warrant was earlier reported by Politico.
The fact that prosecutors quietly obtained a judge’s permission more than seven months ago to peer into Mr. Trump’s Twitter account underscores how much of the special counsel’s work may have taken place out of public view. The bulk of the investigations into Mr. Trump’s efforts to maintain his grip on power and into his other federal case — the one related to his handling of classified materials — have been conducted by federal grand juries, which are governed by strict secrecy rules.
In the chaotic period between the election and Jan. 6, Mr. Trump’s Twitter account, which boasted millions of followers, was one of the country’s most prominent platforms on social media. That prosecutors asked for a warrant to search the account suggests they were interested in some nonpublic aspect of it — though it remains unclear precisely what that was.
As part of their sprawling investigation, prosecutors have seized cellphones and other electronic devices from some of Mr. Trump’s close aides and lawyers. Among those who have had their phones seized are at least two people identified as the former president’s co-conspirators in the indictment against him filed this month: John Eastman, a lawyer who advised Mr. Trump on a plan to pressure his vice president, Mike Pence, into throwing the election his way at a joint session of Congress on Jan. 6, and Jeffrey Clark, a Justice Department loyalist who Mr. Trump sought to install as acting attorney general.
The election charges filed against Mr. Trump accuse him of three overlapping conspiracies to defraud the United States, to disrupt the certification of the election at a proceeding at the Capitol on Jan. 6, and to deprive people of the right to have their votes counted.