House Democrats say former President Trump was “singularly responsible” for the January 6 insurrection at the U.S. Capitol in a legal brief filed Tuesday ahead of next week’s impeachment trial. The lawmakers write, “[Trump] summoned a mob to Washington, exhorted them into a frenzy, and aimed them like a loaded cannon down Pennsylvania Avenue.” They also argue Trump’s baseless claims of election fraud helped rile up his base.

Trump’s lawyers wrote in their own brief that Trump had a right to question election results, and that the trial is unconstitutional since he is no longer in office.

Meanwhile, President Joe Biden paid his respects to Capitol Police officer Brian Sicknick, who lay in honor at the Capitol Rotunda, on Tuesday evening. Five people lost their lives in the January 6 insurrection. Two officers died by suicide following the attack.