[cnn-photo-caption image=http://i2.cdn.turner.com/cnn/2009/images/07/29/am.intv.emerson.homegrown.terrorism.art.jpg caption="Emerson says if an individual is constantly fed a diet that the U.S. Government is an enemy he will naturally end up radicalized."]

The feds are searching for an eighth suspect accused of being part of a terrorist cell in North Carolina. Their alleged ring leader is accused of hoarding weapons and visiting terror camps overseas. This is just one in a string of recent reports of alleged terrorists here at home. So how safe is America from home grown terrorism?

Steven Emerson, the executive director of the Investigative Project on Terrorism spoke with CNN’s Carol Costello Wednesday.

Carol Costello: So it seems like there are a lot of people here in America, alleged home grown terrorists, being indicted for crimes for jihad. How scared should we be?

Steve Emerson: We’re seeing a new phase, Carol, here, in the radicalization of American citizens as well as American-born Muslim. In the past six months alone, there have been more than 40 arrests of either American-born Muslims or of Americans who converted to Islam in trying to carry out plots overseas or in the United States. This is indicative of what has happened in Europe over the last ten years where the environment there and some of the calls by the Islamic groups have radicalized the Muslim populations there. Were seeing it here but more interestingly we’re seeing American citizens who convert to Islam and stage operations from the safety of overseas and carry out jihad.

Costello: I want to talk specifically about Daniel Patrick Boyd, the guy from North Carolina. He just looked like your average Joe. Neighbors said if he was the terrorist, he's the nicest terrorist we know. He just seemed like such a normal guy. Yet he supposedly carried on this secret life. From 1989 to 1992, he traveled to Pakistan and Afghanistan. What did he do there, exactly?

Emerson: Well, in 1989 to 1992, he volunteered against the Soviets who had occupied Afghanistan and he volunteered and trained with the Afghan Mujahedin, the holy warriors. But he kept up and he was interviewed in ‘The Washington Post,’ actually, in 1991 where he called the US a ‘kufr’ or an ‘infidel country.’ He kept up his religious animosity to the United States; even indoctrinating his own kids willing to send them on suicide operations in Israel and elsewhere abroad to carry out jihad. So it shows you the extent to which he was radicalized. What's more interesting here is the extent to which there are other cells across the country, Carol, that have been involved in carrying out plots either here in the U.S. and overseas but using the safety of the United States and becoming radicalized here, even though they were originally not radical or not even born Muslim.

Costello: I want to get to some of the psychology of this. Because Daniel Patrick Boyd allegedly plotted these terror missions overseas, not here in the United States. But then again, who knows, right? But how does one who lives in America, grows up in the American culture, become radicalized like this?

Emerson: You’ve raised an excellent question. I think part of the question lies in the fact that once you make the conversion to Islam, and most Muslims are not radical. Once you make a conversion to Islam, sometimes the Islamic groups, the national groups that control the distribution of literature, of the media, of the educational system, teach them jihad and teach them that the United States is the enemy. Just the other day, letters from Congress representing seven Islamic radical groups claimed to be mistreated by the U.S. government and they themselves in statements in the last ten years have been saying the U.S. government is the enemy. If you constantly are fed a diet that the U.S. Government is an enemy, that the U.S. government is part of the conspiracy to suppress Islam; you will naturally end up radicalized, hating the U.S. and even willing to carry out violence to advance that goal.