Thirteen people were killed April 3 when an embittered gunman opened fire at an immigrant assistance center in Binghamton, New York.

Most of the victims were taking an English class together when Jiverly Wong burst into the room and started shooting.

The shooting began about 10:30 a.m. but it was not a spontaneous act. Wong wore body armor and strode through the American Civic Association's front door only after parking his car to block the back door. He knew the layout — until March he had been taking English lessons there.

Armed with two legally acquired handguns — a 9 mm and a .45-caliber — he shot two receptionists, killing one, then moved on to the classroom where he claimed 12 more victims and killed himself before any confrontation with police.

The 41-year-old Wong, an ethnic Chinese raised in Vietnam who had legally changed his surname to Voong, had recently been laid off, and partly blamed his inability to find and keep work on his poor English-language skills.