WASHINGTON (Reuters) -The congressional panel investigating the Jan. 6, 2021, U.S. Capitol attack may make a criminal referral to the Justice Department recommending that anybody who tried to influence testimony be prosecuted, Representative Liz Cheney said in an interview broadcast on Thursday. The witness-tampering issue emerged during the Jan. 6 select committee’s sixth hearing on Tuesday, when Cheney revealed that some witnesses reported receiving veiled threats from allies of former President Donald Trump to do “the right thing.” “It gives us a real insight into how people around the form…