Anita Brikman: Fairfax County Police trained for terror attacks today as mounting evidence shows that training will be put to use fighting terrorists from right here in the United States.

Derrick McGinty: That's right. More and more terrorist attempts are coming from closer and closer to home, so police and intelligence agencies have to adapt. And as Gary Nurenberg tells us, the changing face of terror now looks more and more like one of our own.

Gary Nurenberg: The training is different now, changes with the changing tactics of terrorists.

Male: Whatever the newest trends are, we try to train to combat those threats.

Male: Basically it's really preparing for worst case scenario.

Nurenberg: Increasingly worst case may be worst case because terrorist planners know American vulnerabilities so well.

Roy Locker: Since beginning of last year we've noticed a marked increase in homegrown terrorism incidents.

Nurenberg: The November Fort Hood shootings that killed 13 and wounded 39, the attempted car bombing in Times Square in May. Just two examples, American citizens planning each.

Locker: I think you're going to see more of this.

Nurenberg: Ray Locker of the Investigative Project on Terrorism says maybe a lot more.

Locker: -have so many things that law enforcement is paying attention to that perhaps a bigger attack slips through. That they're worried about domestic terrorism and somehow somebody from the outside could do something that's even worse.

Nurenberg: One reason why they prepare for homegrown terror attacks even as they try not to lose sight of the threat from abroad.

Nurenberg: And in the immediate future look for increasing levels of scrutiny as we approach a terror milestone in the days ahead, the ninth anniversary of 9/11 is just three weeks from tomorrow. Derrick.