Cassidy Hutchinson testified that Donald Trump was aware that demonstrators on January 6th were armed. Hutchinson said she overheard Trump say ‘I don’t f’ing care that they have weapons. They’re not here to hurt me. Take the f’ing mags [metal detectors] away. Let my people in. They can march the Capitol from here. Let the f’ing people in. Take the mags way.’ Trump still instructed the crowd to head towards Capitol Hill, telling them he'd be there with them. 
Trump knew supporters had guns when he urged march on Capitol, aide testifies
Jan 6 committee hearings live: Trump tried to grab car steering wheel to go to Capitol, ex-aide testifies