As I said, Keitt wasn’t going to shoot anyone. He and Edmundson were there to prevent any interference. Brooks was not attempting to murder Sumner, either. An attempt to charge him with such would’ve been absurd. Had he borrowed Keitt’s pistol (or used his own) and shot him down, that would’ve been attempted murder (as Brooks said himself, if he was going to kill him, he’d not have used his cane).
I found more troubling that of MA Congressman Anson Burlingame wanting to avenge the beating by murdering Brooks (taking advantage of the fact that Burlingame was an excellent shot), and he wanted to do so on foreign soil in Canada. Brooks did not accept such a challenge, because it was obvious this was an attempt to murder.
I wonder how Keitt would have liked it if I held a gun on him to prevent his interference while my friend violently beat his father or someone he liked half to death. He might think it a crime.
He deserved his censure and far worse.
As for Burlingame, sounds like BROOKS challenged him to a duel but wussed out like the chickenbleep loser he was when he heard Burlingame was a good shot. What a loser.