The only crongressman to kill another congressman was on February 24, 1838, according to my google-fu.
On this date, Jonathan Cilley of Maine was killed by Representative William Graves of Kentucky in a duel on the outskirts of D.C., in Prince George’s County, Maryland.
At least he did not do this in the building itself.
The attack with the cane is well known, I believe:
The Senate had just adjourned on May 22, 1856, when Representative Preston Brooks entered its chamber carrying a cane. The pro-slavery southerner walked over to Senator Charles Sumner, whacked him in the head with the cane and then proceeded to beat the anti-slavery northerner unconscious. Afterward, Brooks walked out of the chamber without anyone stopping him.
I see Trump fantasizing about this, but he could not do it himself, not even with a golf club. I mean, the man needs a valet* to tie his shoelaces…
But there once was a shooting in congress. It was the Ticos!. 1954, those were different times:
[Speaker] Martin later recalled, “Bullets whistled through the chamber in the wildest scene in the entire history of Congress . . . ‘The house stands recessed,’ I declared, unhindered by any parliamentarian.” […]
I believe the pandemonium today would be a of different order of magnitude. It would be shown live on TV, and it would become trending topic in the so called social media in no time at all. I can imagine tanTrump boasting afterwards (if he survived) that he had higher quotas than the 9/11 losers.
* Strange, my fingers almost wrote wallet instead all on thier own.