Rudy Giuliani, a personal attorney for Donald Trump, said this week that he will not represent the president at his second impeachment trial.
According to ABC News, Giuliani initially said that he had been working on a defense centered around the idea that Trump cannot be guilty of inciting a riot because his false claims about a "stolen" election are true.
But Giuliani backtracked after a meeting with Trump at the White House on Saturday.
"Because I gave an earlier speech [at the rally], I am a witness and therefore unable to participate in court or in the Senate chamber," the president's attorney told ABC News.
While speaking at the rally that triggered the Capitol Hill siege, Giuliani implored the crowd to engage in "trial by combat."
A police officer and four other people later died in the attack on the Capitol.