The victims, police said, included 12 people preparing for tests to become US citizens, and a receptionist. Her colleague, hit in the stomach but alive, called 911 from under her desk at 10.30am yesterday, as dozens of other visitors at the centre cowered in a boiler room and parts of the town were locked down.
The gunman, named by other sources as Jiverley Voong, from nearby Johnson City, had driven to the back of the American Civic Association building in a borrowed car, said the police chief Joseph Zikuski. "It was obviously premeditated," he said. "He put the car right against the door to make sure no one could get out."
Swat teams descended on the centre within minutes, and a professor was summoned from a local college to translate Vietnamese as police communicated with 37 survivors inside the building, but no more shots were fired. When they finally entered, police found that Mr Voong had shot himself in the head. A satchel full of ammunition was found around his body.
The horror in Binghamton came less than a month after a man killed 10 people, many of them family members, in a shooting rampage in Alabama. Last night, familiar rituals: an outpouring of sympathy, this time for a town of 45,000 residents, 150 miles north-west of New York City; another round of handwringing from politicians, from the Vice-President down.
"We've got to find a way to deal with this senseless, senseless violence," Joe Biden told an audience in New York. The state's governor, David Paterson, who flew to Binghamton last night, asked: "When are we going to be able to curb the kind of violence that is so fraught and so rapid that we can't even keep track of the incidents?"
For more than three hours after police arrived, they treated the incident as a potential hostage situation, fearful that the gunman might still be at large in the centre. Nearby high schools were told to lock children in. Police requested plans showing the layout of the civic centre. Local television stations showed officers armed with rifles, some carrying shields, deployed around the building. Survivors who matched the receptionist's description of the attacker were led out in plastic handcuffs, until police could satisfy themselves they were not the killer.
At a press conference, Mr Zikuski praised his police force and the FBI for dealing well with an incident that had come like a bolt from the blue. "This is Binghamton, we don't have these tragedies," he said.
*29 March 2009: Robert Stewart, 45, killed seven residents and a carer at a nursing home in North Carolina.
*10 March 2009: Michael McLendon, 28, killed 10 people in Alabama, before killing himself.
*14 February 2008: Steven Kazmierczak, 27, shot dead five students in DeKalb, before killing himself.
*16 April 2007: Seung-Hui Cho, 23, shot dead 32 people then killed himself at Virginia Tech. The incident was the deadliest mass shooting in US history.