President Biden ordered flags at the White House to be flown at half-staff in honor of Officer Evans, and Speaker Nancy Pelosi ordered the same at the Capitol complex.
“We send our heartfelt condolences to Officer Evans’s family, and everyone grieving his loss,” Mr. Biden, who served in the Senate for 36 years, said in a statement. “We know what a difficult time this has been for the Capitol, everyone who works there, and those who protect it.”
Senator Mitch McConnell of Kentucky, the Republican leader, said Officer Evans’s name would “go down in history for his selfless sacrifice.”
The violence came on a quiet afternoon just as the Capitol had seemed to be getting back to normal after the trauma of Jan. 6, the most violent attack on the Capitol in two centuries, and months of heightened security measures.
In a matter of minutes on Friday, the entire complex was put on lockdown for over an hour, as reporters and Capitol staff members were left to press up against windows to catch sight of the unfolding chaos with little information about the scale of the threat.
A helicopter swept across the plaza in front of the Capitol, landing only feet away from the building. At least one of the officers was medevacked to a hospital, according to law enforcement officials, and a National Guard quick-response team and the local police were on hand at the already heavily fortified complex.