BINGHAMTON, N.Y. — The night before the killings, Son Quach spotted a former co-worker playing racquetball alone at a gym here called the Court Jester. It was the third time he had seen the man, Jiverly Wong, at the gym that week.
Mr. Wong told Mr. Quach, speaking in their native Vietnamese, that he had been laid off and was living on $200 a week in unemployment benefits. He spent so much time at the gym, Mr. Quach said, because he could not find a job.
The next morning, according to the police, Mr. Wong, 41, burst into the headquarters of the American Civic Association, where until recently he had been taking classes to improve his English, wearing body armor and firing two handguns, killing 13 students and employees and wounding four others before committing suicide. The shootings on Friday were the nation’s worst killings since the 2007 massacre at Virginia Tech.
“At one point in his thinking process, he was going to take the police on — or at least try to stop us from stopping him,” Chief Joseph Zikuski of the Binghamton police said on Saturday, referring to Mr. Wong’s bullet-resistant vest. “He must have been a coward,” Chief Zikuski added. “When he heard the sirens he decided to take his own life.”
The details of Mr. Wong’s life and the way it ended were still being investigated, but in the buildup to the killings there were hints of mounting frustration and evidence of premeditation. Like many of those who were killed, Mr. Wong was an immigrant, striving to gain a toehold in the United States as he moved between California and upstate New York. But he seemed to have hit a wall, struggling to improve his English, dependent on government aid and unable to find financial stability amid the worst economic crisis in decades.
Chief Zikuski said that to people close to Mr. Wong, “the actions that he took were not a surprise to them.”
“He felt that he was degraded because of his inability to speak English, and he was upset about that,” Chief Zikuski said. “This behavior on his part wasn’t a total shock.”
But to many who knew him, the sudden violence did not fit the man they knew. People who worked with Mr. Wong, at a local Shop-Vac factory, on an I.B.M. line in Endicott, N.Y., and at a sushi delivery company in California, described him as amiable but reserved and someone who kept to himself more because of his limited English than because he was a loner.
He was also a gun enthusiast who often spent weekends shooting targets and trying out different guns at a local sporting goods store. He had been licensed to carry handguns in New York since 1996, the police said.
Neighbors in Union, outside Binghamton, where Mr. Wong lived with his parents and a sister, said they knew Mr. Wong’s father as a kind man who grew grapes in the backyard and apples in the front. They sometimes saw the younger Mr. Wong mowing the lawn but otherwise said he mostly stayed inside when he was home.
On Saturday, his family posted a sign outside their two-story house saying, “No press, please.”
Chief Zikuski said Mr. Wong, who the police say also used the last name Voong, caught the attention of law enforcement officials in 1999 after they received a tip that he was planning a bank robbery and had a crack cocaine habit. He had a “criminal incident” out of state, the authorities said, but they provided no details.
Mr. Quach said he worked with Mr. Wong at I.B.M. in Endicott about seven or eight years ago taking apart computers. When they saw each other at the gym that week, Mr. Wong told him that he had moved to California because he could earn more money there, as a truck driver, and that he had a girlfriend. “He said after he got laid off she say, ‘Bye-bye,’ ” Mr. Quach said. “I said, ‘Maybe she loves your money.’ He smiled.”
Hue Huynh, 56, Mr. Quach’s wife, who is a clerk at Vietnamese market on Main Street in Binghamton owned by her brother, was with her husband when they saw Mr. Wong at the gym.
“He told my husband, ‘I’m very upset I don’t have a job,’ ” Ms. Huynh recalled.
“He said he tried to find a job but nobody like him.” She said her husband tried to reassure him: “He told him, ‘You’re still young, you will be okay, you will get a job again.’ ”
“He was a nice boy,” Ms. Huynh added. “He had bad luck, he went everywhere but no good job for him.”
Between 2000 and 2007, Mr. Wong worked at Kikka Sushi in Inglewood, Calif., near Los Angeles, earning $9 an hour as a driver until he failed to show up for work one day, said Paulus Lukas, a human resources employee for the company. Mr. Wong made few friends and rarely socialized, he said, “but didn’t have any personal problems or anything like that that we know of.”
At Shop-Vac in Endicott, which closed last year and where Mr. Wong apparently worked next assembling vacuums, he was known simply as Wong and wore jeans and T-shirts emblazoned with the New York Yankees logo.
David Ackley, 18, who worked with Mr. Wong at Shop-Vac for a few months, said he would often say that he had spent the weekend at a firing range, and joked about shooting politicians.
“I asked him who he was going to vote for, and he said, ‘I don’t really care, I’d shoot both of them,’ ” recalled Mr. Ackley, whose father, Donald, also worked at Shop-Vac. When the elder Mr. Ackley told Mr. Wong, “You better watch out, I’m going to call the F.B.I.,” he said Saturday. Mr. Wong responded, “I’m just joking around.”
The two men said that they often talked to Mr. Wong during breaks, but that the language barrier meant mostly superficial conversations.
“I asked him once about wife and kids,” Donald Ackley said. “He said he had a daughter in California, I think Los Angeles, but he never talked about it again.”
Mr. Wong was laid off, along with everyone else, the day before Thanksgiving, a fact that left many workers embittered, Donald Ackley said. But Mr. Wong seemed unperturbed, he said, and instead sought help filing for unemployment.
“You think he would have been disgruntled about that,” Mr. Ackley said. “What would have stopped him from coming to Shop-Vac and killing all of us?”