The gunman who killed 13 people in a rampage at an immigrant community center and then committed suicide was wearing body armor, indicating he was prepared to battle with law enforcers, the Binghamton police chief said Saturday.

The gunman, 41-year-old Jiverly Wong, had been taking classes at the American Civic Association, which helps immigrants assimilate, until last month, Police Chief Joseph Zikuski said.

Wong had a permit for the two handguns he used, Zikuski said. Most of the victims had multiple gunshot wounds, he said.

Wong, who used the alias Jiverly Voong, believed people close to him were making fun of him for his poor English language skills, Zikuski said.

Wong was ethnically Chinese but from Vietnam, a friend said Saturday. He was angry about recently losing a job, couldn't find work and complained that his unemployment checks were only $200 a week, said Hue Huynh, a Binghamton grocery store proprietor whose husband worked with Wong years ago.

Wong had driven a truck in California before recently returning to Binghamton, only to lose a job there, Huynh said.

"He's upset he don't have a job here. He come back and want to work," she said. Her husband tried to cheer him by telling him he was still young and there was plenty of time to find work, but he complained about his "bad luck," she said.

On Friday, Wong barricaded the American Civic Association community center's back door with his car, walked in the front and started shooting with two handguns. Within minutes, a receptionist, 12 immigrants taking a citizenship class and the gunman were dead.

Another receptionist, 61-year-old Shirley DeLucia, played dead after she was shot in the abdomen and called 911 to get police to the scene within two minutes.

Zikuski said the injured receptionist stayed on the phone for 90 minutes, "feeding us information constantly," despite a serious wound in the abdomen.

"She's a hero in her own right," he said.

DeLucia was in critical condition at a hospital Saturday, along with another victim in the same condition and another in serious condition. A fourth victim was in stable condition at another hospital.

Thirty-seven others made it out, including 26 who hid for hours in a basement boiler room while police tried to determine whether the gunman was still alive and whether he was holding any hostages, Zikuski said.

Investigators said they had yet to establish a motive for the shooting. It was at least the fifth fatal mass shooting in the U.S. in the past month, and the nation's deadliest since April 2007, when 32 people and a gunman died at Virginia Tech.

Wong was found dead in an office with a self-inflicted gunshot wound, a satchel containing ammunition slung around his neck, authorities said. Police found two handguns _ a 9 mm and a .45-caliber _ and a hunting knife.

A woman who answered the phone at a listing for Henry D. Voong said she was Jiverly Voong's sister but would not give her name. She said her brother had been in the country for 28 years and had citizenship.

Accounts varied about the suspect's work history. Zikuski told NBC's "Today" show that the shooter had worked in Binghamton for Shop-Vac, which closed in November. The sister told the AP on Friday that her brother worked at a company where "they make the vacuums."

Initial reports suggested Voong had recently been let go from IBM, which has roots in the region, but a person at IBM said there was no record of a Jiverly Voong ever working there. His father, Henry Voong, does work there as a contractor.

Huynh said her husband had worked with Voong years ago at IBM and that he had recently been let go from IBM again after returning from California.

The attack at the American Civic Association, which helps immigrants settle in this country, came just after 10 a.m. as people from all over the globe _ Latin America, China, Kazakhstan, Vietnam, Africa _ gathered for English and citizenship lessons in an effort to become a bigger part of their new home.

Wong parked his car against the back door before barging through the front and opening fire, apparently without saying a word. He then entered a room just off the reception area and fired on a citizenship class while terrified people scrambled into a boiler room and a storage room.

Abdelhak Ettouri, a Moroccan immigrant who lives in nearby Johnson City, told the Binghamton Press & Sun-Bulletin he found the back door locked when he tried to flee, then ran to hide in the basement as he heard 12 to 14 shots: "Tak-tak-tak-tak."

Hoi Nguyen of Binghamton said his 36-year-old daughter Phuong Nguyen, who survived the massacre, was taking an English class in the basement when the gunfire started.

"She said it sounded like a firecracker and everyone in the class was startled," he said. "Then the teacher locked the door, called the police, then told everyone they couldn't leave the room."

Police arrived in minutes, heard no gunfire and waited for about an hour before entering the building to make sure it was safe for officers. They then spent two hours searching the building. They led a number of men out in plastic handcuffs while trying to sort out victims from the killer or killers.

The shootings took place in a neighborhood of homes and small businesses in downtown Binghamton, a city of about 47,000 situated 140 miles northwest of New York City.

The region was the home to Endicott-Johnson shoe company and the birthplace of IBM, which between them employed tens of thousands of workers before the shoe company closed a decade ago and IBM downsized in recent years.

A string of attacks in the U.S. in the last month left 44 people dead in all.

A gunman killed 10 people and himself in Samson, Ala.; shootings that began with a traffic stop in Oakland, Calif., left four police officers and the gunman dead; an apparent murder-suicide in Santa Clara, Calif., left six dead; and a gunman went on a rampage at a nursing home Sunday, killing seven elderly residents and a nurse who cared for them.

___

Contributing to this report were Associated Press writers Michael Hill, John Kekis and Michael Rubinkam in Binghamton; Carolyn Thompson and John Wawrow in Buffalo, N.Y.; Jessica M. Pasko, George M. Walsh and Chris Carola in Albany; Ben Dobbin in Rochester, N.Y.; Daisy Nguyen in Los Angeles; and the AP News Information Research Center in New York.