Authorities say Jiverly Wong, 41, of nearby Johnson City, N.Y., in the American Civic Association before turning the gun on himself.
What could have led Wong down his murderous path?
"After studying mass killings for more than 25 years, I can tell you that, in almost every case, the motive is revenge," criminologist Jack Levin told co-anchor Erica Hill on The Early Show Saturday Edition.
Levin, co-director of the Brudnick Center on Violence at Northeastern University, in Boston, is widely regarded as one of the foremost authorities on mass murderers, serial killers and hate crimes.
Police say Wong had been laid off, was angry, and thought people looked down on him.
"It seems to me," Levin observed to Hill, "that, in this case, Wong was on a suicidal rampage. He was going to take his life, but first he was going to get even. He was going to get sweet revenge against the other immigrants who had looked down upon him, among whom he had lost face. To him, that was an extremely important thing.
"He had already suffered a catastrophic loss, by losing his job in a layoff, but he also lost respect in the eyes of the immigrant population, and blamed (the American Civic Association), which was responsible, or at least had a mandate to teach, language skills and job training, and those were the things that he lacked."
Hill pointed out it's "very frightening" to think a job less might have been the final straw for Wong, considering how many people are out of work in this economy. So, she asked, are there any clues that could tip off others to potentially violent intentions of people bent on revenge.
"You know, we live in a country that has plenty of personal freedom." Levin responded. "What are we going to do? Lock up every building, hoping to make it a safe haven? I don't think so. We can try to reduce the proliferation of semi-automatics (guns); that might work to some extent, the body counts would be lower, I guess.
"But the point is that there are millions of people out there who are like this killer. They're depressed. They blame everybody but themselves. They're socially isolated. You know, that's the profile. And yet they never kill anyone."
So then what makes somebody snap?
"First of all, I don't think he snapped," replied Levin (left). "This was a methodical, well-planned crime. You know, after all, he barricaded the back door with a car. He came with an arsenal of weapons, slung over his shoulder. No, this was planned. He didn't go berserk. But I think that's a very good point. What does make someone translate that kind of depression and frustration with everyday life, and it is a catastrophic loss.
"In his eyes, something just horrendous went wrong, and that was the triggering event, losing his job, losing respect in the eyes of the other members of the community, and that was enough to push him over the edge."