Former US special counsel Jack Smith has said the January 6, 2021, attack on the US Capitol would not have happened without Donald Trump, characterizing the Republican president as the “most culpable and most responsible person” in the criminal conspiracy to overturn the results of the 2020 election.

A transcript and video of Smith’s closed-door deposition were released on Wednesday by the Republican-controlled House Judiciary Committee. During the testimony, Smith defended the basis of his investigations and rejected claims that they were politically motivated.

Smith said the evidence showed that Trump fuelled false claims of election fraud, summoned supporters to Washington and directed them toward the Capitol. He added that once violence broke out, Trump failed to act promptly to stop it and instead made statements that further escalated the situation and endangered then Vice President Mike Pence.

Trump had been indicted for conspiring to overturn the 2020 election and for illegally retaining classified documents at his Florida residence. However, both cases were abandoned after Trump won the 2024 presidential election, in line with US Justice Department policy barring prosecution of a sitting president.

Smith said the January 6 case relied heavily on testimony from Republican allies who acknowledged the illegality of the actions and chose loyalty to the Constitution over party interests.