There were prayers and expressions of sympathy for the victims after a gunman opened fire on Republicans practising for a charity baseball game, but no signs of any new push in the US Congress to tighten gun-control laws .
Steve Scalise, the No. 3 Republican in the House of Representatives, was shot in the hip and was in a critical condition after surgery.
In a country where there are almost as many guns as people, gun ownership is fiercely defended by firearms industry lobbyists and Republican politicians, who now control the Senate, the House of Representatives and the White House.
In addition to the shooting at a baseball field in Alexandria, Virginia on Wednesday, a man dressed in a UPS uniform and armed with an "assault pistol" opened fire at a United Parcel Service package sorting hub in San Francisco, killing three people before turning the gun on himself, police said.
Also, one man was shot outside a shopping centre near a major sports arena in New York City on Wednesday but it was not immediately clear who opened fire or how badly the victim was hurt, police said.
Despite the day's carnage, there was no immediate indication that President Donald Trump or his fellow Republicans would shift from their position protecting gun ownership rights. Pro-gun voters lean heavily toward the Republican Party.
The lawmakers did not indicate gun control was discussed. Typically after mass shootings, politicians are hesitant to talk about partisan legislative matters.
Spokesmen for the National Rifle Association (NRA), the powerful pro-gun rights lobbying group and a Republican Party ally, were not immediately available for comment.
Democrats, who generally, though not uniformly, are more aggressive about gun control laws, expressed concern following the Alexandria incident, in which Republican Representative Steve Scalise and several other people were shot.
"There are too many guns on the street," said Virginia Governor Terry McAuliffe, a Democrat.
Scalise, the No. 3 Republican in the House, has worked to oppose new federal gun controls that he has seen as an assault on the US Constitution's Second Amendment right to bear arms.