Is the economy a factor in recent shootings?

Recent incidents differ, but experts say there could be a trend.

Details continue to emerge from Binghamton, New York, where a gunman identified as Jiverly Voong, 41, barricaded the back door of the American Civic Association Friday morning, then went in the front door shooting at everyone in the room, killing 13 and then shooting himself.

Early reports say the gunman was deeply upset over being laid off and for being disrespected for not speaking English well.

That event, as well as three policemen wounded in a Pittsburgh shooting after responding to a domestic disturbance call – friends said that gunman was also upset about his recent firing – fit a larger pattern of mass killings which have seemed to proliferate since America's economic downturn, experts say. Forty-four people have died in a string of five such incidents in the past month, from Oakland, California to Alabama to North Carolina.

Monitor reporter Patrik Jonsson reported on this trend earlier this week.

Voong "had lost a job recently and was somewhat angry," Mayor Matthew Ryan told ABC's "Good Morning America." "He had language issues, didn't speak English that well, and was really concerned about his employment situation," Ryan said.

Police Chief Joseph Zikuski told NBC that the shooter had worked in Binghamton for Shop-Vac, which closed in November. And early reports claimed Voong had been laid off from IBM, although an IBM spokesman has denied the link. Henry Voong, Jiverly Voong' father, works there as a contractor.

Immigrant groups across the nation have been expressing sadness and concern about the Binghamton shootings, and mentioning the pressure of the down turned economy.

"Violence against vulnerable populations, including immigrants, is disturbingly becoming more common now that the economy is impacting us all," wrote Angelica Salas, executive director of Coalition for Humane Immigrant Rights of Los Angeles (CHIRLA) said in a statement Saturday.

Criminologists say other cultural factors could be at play as well – ranging from the possibility of shame and embarrassment for immigrants as well as the modern isolation of men in US society.

"Men in America tend to not have a support system outside work to get through hard times," says James Allan Fox, professor of criminal justice at Northeastern University in Boston, and author of "Extreme Killing: Understanding Mass and Serial Murder. "Men rarely have friends outside work so when they lose their job they lose all the people that were around them and they feel abandoned."

More important, community doesn't just offer support but perspective, says Fox.

"Men also lose anyone who might give them a reality check on their attitude or behavior," he says, adding that they lose something as "simple as a buddy who could lean over and say, 'think again.'"

Fox and others are quick to point out that clusters of mass murders are not new. They happened in earlier decades. What stands in stark contrast to an earlier era such as the 50s and the 70s is a disintegration of neighborhoods and tight-knit communities.

"People today don't know their neighbors, don't know what they do and certainly don't know what to say if they lose their job," Fox says. He suggests that if people wonder what they can do in response to such extreme circumstances, they should consider reaching out to people they don't know and even "getting to know their neighbors."

Staff writer Gloria Goodale contributed to this report.