After Joe Biden won the 2020 election and Trump refused to concede, baseless claims of voting fraud circulated. Barr sent a memo to DOJ prosecutors authorizing them to investigate "vote tabulation irregularities" before voting results had been certified, a reversal of long-standing department policy. Richard Pilger, director of the Election Crimes Branch at the DOJ Criminal Division, stepped down from that position in protest hours later. Four days later, sixteen assistant U.S. attorneys of the Branch wrote Barr a letter urging him to rescind the memo because it "thrusts career prosecutors into partisan politics". Barr later told a journalist that he had always expected Trump's electoral loss and never expected that Trump's fraud claims would have merit: "My suspicion all the way along was that there was nothing there. It was all bullshit." However, he asserted that because he expected Trump to ask him for details, he informally investigated to educate himself. Some asserted Barr's statements during the campaign suggested otherwise and that he was now attempting to rehabilitate his reputation. Barr waited until December 1, 2020, to state that the Justice Department "has not uncovered evidence of widespread voter fraud that would change the outcome of the 2020 presidential election". Trump was angered by the announcement and the fact that Durham had not released any findings prior to the election. Trump was also angered by news that Barr had followed Justice Department policy by not disclosing during the campaign that Joe Biden's son Hunter had since 2018 been under criminal investigation, initially on suspicion of money laundering but later for tax matters. On December 14, 2020, Trump announced on Twitter that Barr was stepping down from his post on December 23. After a pro-Trump mob stormed the U.S. Capitol after being incited by Trump, Barr said Trump had committed a "betrayal of his office".