Antiterrorism officials say the evidence from recent arrests in Chicago, Detroit, Minneapolis, New York, and other US cities, paints the picture of American citizens getting radicalized in their local communities, attending training camps in Pakistan or Somalia, and then returning to the US to help assist international terrorist bosses plan attacks in other countries or possibly, on these shores.
Report: five Americans arrested in Pakistan
In what could be the most recent example, Pakistani authorities said Wednesday that they have arrested five American men, and preliminary investigations suggest the men were seeking to link up with terrorist organizations in Pakistan. Reports suggest the five men are from Virginia, and their families alerted the FBI when the men went missing.
Last week, Department of Homeland Security Secretary Janet Napolitano told an audience in New York City that "home-based terrorism is here. And like violent extremism abroad, it is now part of the threat picture that we must confront."
But there is disagreement about how these terrorists are radicalized and what is the most effective way to prevent it.
"It's a huge concern because one of the things that US intelligence does very well is track known members of Al Qaeda overseas," says Howard Safir, New York City Police Commissioner from 1996 to 2000. "But what they don't know and what is really harder to determine ... are who I call the 'independent entrepreneurs' — the folks who are committed to jihad but who are not members of any specific organization."