“Someone pointed to a gun-like object in the hand of a man in the crowd. The witness informed the police officer who detained the suspect,” the police said in a message on Twitter.
Later, the police found that the man was indeed armed.
Two more were arrested on warrants issued in Texas, another for violating the conditions of release.
Trump supporters on Saturday held a rally at the Capitol in support of those who are accused in the case of the storming of the Congressional building on January 6.