Ever since Sept. 11, U.S. authorities have asked the public to be vigilant, urging, "If you see something, say something."

In January 2006, a store clerk in New Jersey saw something.

A group of men had brought him a video showing them firing assault weapons and chanting, "God is Great!" in Arabic. They wanted him to transfer the footage onto a DVD.

So he said something, calling the Mount Laurel Police Department, who in turn contacted the FBI.

And thus began the downfall of one of the most thoroughly infiltrated and documented group of terrorism suspects in recent history — six men from Yugoslavia and the Middle East who were charged Tuesday with plotting to slaughter scores of American soldiers at Fort Dix and perhaps other military installations in the Northeast.

Click here to read the complaint (FindLaw pdf)

FBI agent J.P. Weis saluted the unidentified Mount Laurel store clerk as the "unsung hero" of the case.

"That's why we're here today — because of the courage and heroism of that individual," the FBI agent said.

The suspects' images and words were captured on more than 50 audio and video recordings. Their comings and goings were recorded by law enforcement agents who monitored the alleged plot for 16 months, hoping more terror ties would become apparent.

The defendants, all men in their 20s, include a pizza deliveryman suspected of using his job to scout out Fort Dix. Their goal was "to kill as many American soldiers as possible" in attacks with mortars, rocket-propelled grenades and guns, prosecutors said.

"Today we dodged a bullet. In fact, when you look at the type of weapons that this group was trying to purchase, we may have dodged a lot of bullets," Weis said. "We had a group that was forming a platoon to take on an army. They identified their target, they did their reconnaissance. They had maps. And they were in the process of buying weapons. Luckily, we were able to stop that."

Authorities said there was no direct evidence connecting the men to any international terror organizations such as Al Qaeda. But several of them said they were ready to kill and die "in the name of Allah," according to court papers.

The six men — five of whom lived in Cherry Hill, a Philadelphia suburb about 20 miles from Fort Dix — were arrested Monday night while trying to buy AK-47 assault weapons, M-16s and other weapons from an FBI informant, authorities said.

"This is what law enforcement is supposed to do in the post-9/11 era — stay one step ahead of those who are attempting to cause harm to innocent American citizens," U.S. Attorney Christopher Christie said.

In addition to plotting the attack on Fort Dix, the defendants spoke of attacking a Navy installation in Philadelphia during the annual Army-Navy football game and conducted surveillance at other military installations in the region, prosecutors said.

One defendant, Eljvir Duka, was recorded as saying: "In the end, when it comes to defending your religion, when someone ... attacks your religion, your way of life, then you go jihad."

"It doesn't matter to me whether I get locked up, arrested or get taken away," another defendant, Serdar Tatar, was alleged to have said. "Or I die, it doesn't matter. I'm doing it in the name of Allah."

They appeared in federal court Tuesday in Camden and were ordered held without bail for a hearing Friday. Five were charged with conspiracy to kill U.S. military personnel; the sixth was charged with aiding and abetting illegal immigrants in obtaining weapons.

Four of the men were born in the former Yugoslavia, one was born in Jordan and one came from Turkey, authorities said. All had lived in the United States for years. Three were in the United States illegally; two had green cards allowing them to stay in this country permanently; and the sixth is a U.S. citizen.

One defendant, Mohamad Ibrahim Shnewer, spoke of using rocket-propelled grenades and other weapons to kill at least 100 soldiers, according to court documents.

"My intent is to hit a heavy concentration of soldiers," he was quoted as saying. "You hit four, five or six Humvees and light the whole place (up) and retreat completely without any losses."

The men trained by playing paintball in the woods in New Jersey and taking target practice at a firing range in Pennsylvania's Pocono Mountains, where they had rented a house, authorities said.

They often watched terror training videos, clips featuring Usama bin Laden, a tape containing the last will and testament of some of the Sept. 11 hijackers, and tapes of armed attacks on U.S. military personnel, erupting in laughter when one plotter noted that a Marine's arm was blown off in an ambush, authorities said.

Asked if those arrested had any links to Al Qaeda, White House spokesman Tony Snow said it appears "there is no direct evidence of a foreign terrorist tie."

The FBI's Weis said the U.S. is seeing a "brand-new form of terrorism," involving smaller, more loosely defined groups that may not be connected to Al Qaeda but are inspired by its ideology.

"These homegrown terrorists can prove to be as dangerous as any known group, if not more so. They operate under the radar," Weis said.

According to court documents, the video that the store clerk found disturbing depicted 10 young men in their early 20s "shooting assault weapons at a firing range ... while calling for jihad and shouting in Arabic 'Allah Akbar' (God is great)." The 10 included six of those arrested, authorities said.

Within months, the FBI had managed to infiltrate the group with two informants, according to court documents.

One of the suspects, Tatar, worked at his father's pizzeria and made deliveries to Fort Dix, using the opportunity to scout out the base for an attack, authorities said.

"Clearly, one of the guys had an intimate knowledge of the base from having been there delivering pizzas," Christie said.

The men also allegedly conducted surveillance at other area military installations, including Fort Monmouth in New Jersey, Dover Air Force Base in Delaware, and a Philadelphia Coast Guard station.

Besides Shnewer, Tatar and Duka, the other three men were identified in court papers as Dritan Duka, Shain Duka and Agron Abdullahu.

Fort Dix is used to train soldiers, particularly reservists. It also housed refugees from Kosovo in 1999.

The arrests stirred renewed worry among New Jersey's Muslim community. Hundreds of Muslim men from New Jersey were rounded up and detained in the months after the Sept. 11 attacks, but none were connected to that plot.

"If these people did something, then they deserve to be punished to the fullest extent of the law," said Sohail Mohammed, a lawyer who represented scores of detainees after the 2001 attacks. "But when the government says `Islamic militants,' it sends a message to the public that Islam and militancy are synonymous."

"Don't equate actions with religion," he said.