New York was shellshocked this week after three homegrown terror suspects from Newburgh, NY, joined a fourth in a plot to blow up a Bronx synagogue and shoot down US military planes.

The suspects all face potential life sentences if convicted. They are: James Cromitie, 55, the leader of the group, who has spent time in prison; David Williams, 28; Onta Williams, age 32; and Haitian immigrant Laguerre Payen, who is said to have mental problems. The four were arraigned in a White Plains, NY, court Thursday, and didn't seek bail.

The seemingly ragtag group is accused of hatching an anti-Semitic plot to kill Jews and as retaliation for US involvement in Afghanistan. They are being charged with conspiracy to use weapons of mass destruction in the United States and conspiracy to acquire and use anti-aircraft missiles, according to the criminal complaint, but there's no sign they're part of any larger plot. Three of the men reportedly are converts to Islam.

The background: An FBI informant met with Cromitie in Newburgh in June 2008, saying his parents lived in Afghanistan and he was upset so many Muslims were being killed there and in Pakistan by U.S. forces. He talked about going to "paradise" should he die a martyr, and said he wanted to do "something to America." Later, the pair talked about Jaish-e-Mohammed, a designated foreign terrorist organization based in Pakistan, with which the informant claimed to be involved. Cromitie said he wanted to join to "do jihad."

The informant met Cromitie and the others last fall at Cromitie's Newburgh home while they talked about plans to attack New York targets, including military aircraft located at Stewart Air National Guard Base in Newburgh. From Nov. 28-30, Cromitie and the informant traveled to Philadelphia for a meeting of the Muslim Alliance of North America, during which Cromitie said, "the best target [the World Trade Center] was hit already."' He later made anti-Semitic comments toward Jews in reference to an attack on a synagogue. Cromitie asked the informant to get them surface-to-air guided missiles and explosives to attack the Jewish community center in Riverdale, N.Y. - which they thought would be a "piece of cake" to target - and bought a 9-millimeter semi-automatic pistol. Earlier this month, the suspects drove to Stamford, Conn., to get what the informant told them would be surface-to-air guided missile systems and three improvised explosive devices containing C-4 plastic explosives. They brought the dummy weapons back to Newburgh for their attack, but were stopped by police Wednesday night after planting a fake explosive in a car outside Riverdale Temple and two fake bombs outside the nearby Riverdale Jewish Center.

Although prosecutors are portraying the quartet as an extremely violent group out for blood, defense attorneys indicated there's more to the story. Then there's the informant. The imam from the Islamic Learning Center of Orange County (Masjid al-Ikhlas mosque), Salahuddin Muhammad, said he only barely recognized one of the men - even though the FBI said three of them had ties to the mosque, and that the whole ordeal "really put me off," since his mosque engages with people of all faiths. He also said the FBI tactics may amount to entrapment, particularly if the informant offered the seemingly poor suspects money.

“This informant was basically trying to get people to come on, to get involved in something,” he told the Times Herald-Record . “I believe that this person was more than just someone listening in to see if someone had some bad ideas. But I believe that this person was someone who was prompting, prompting, prompting and trying to get people to get on board with this thing.”

Others are also tossing around the idea of entrapment - where a government agent walks into a case where no one has a predisposition to commit the crime and that person incites them to commit a crime they otherwise would not have. Post Sept. 11, the claim is a particularly popular one for terror defendants - the six Muslim men accused in the Fort Dix, N.J., plot, for example, as well as Shahwar Matin Siraj, convicted of plotting to blow up New York City's Herald Square subway station in 2003. But it's very hard to prove.

"If the defendant has any prior history that's relevant to the crime, then the entrapment defense will fail," New York criminal defense attorney Michael Bachrach explained to HSToday.us. "You essentially have to be completely innocent. You have to have no compunction to commit the crime when somebody incites you to do it."

But New York Police Commissioner Ray Kelly says there's "no question about" the suspects' intent.

"Clearly their intention was to kill people ... they were serious," Kelly told CNN on Thursday. "Entrapment is always going to be a defense but you have to not be otherwise disposed to do it. That's in every trial - certainly in every terrorist trial - where there's an informant involved. I don't think that's the case here."

Newburgh is a smaller urban city located about an hour north of Manhattan, and is very diverse - both ethnically and financially. There's some chatter on Facebook amongst some graduates of Newburgh Free Academy - the high-school attended by area students - as to whether some of the younger suspects attended the school. But the school is large, and it's not a place where everybody knows each other. Even though many are incredulous these men could have planned such a thing, still, the thought that the suspects were allegedly hatching the plot in town was a bit unsettling.

"If I did go to school with these guys ... it would just be completely surreal," Suzanne Volpe, a New York attorney and 2000 Newburgh Free Academy graduate told HSToday. "I was not surprised that they were from Newburgh," given how diverse the city is and how close it is to Manhattan, she continued. But "I was a bit bewildered and chagrined. ...I'm sad. These are guys from my hometown ... Newburgh is going to undergo some level of scrutiny it wouldn't normally get."

New York officials are congratulating the New York Police Department, FBI and other law enforcement agencies like the New York Joint Terrorism Task Force involved in the bust, pointing out this case is proof New York hasn't escaped the terror threat.

"This is a city where people want to live together and once again, when we are threatened, NYPD ... are showing they are doing exactly what we would expect," and thwarting such plots, said New York City Mayor Michael Bloomberg. "Time and time again, for the last seven-and-a-half years, when we've been threatened, we've discovered it and we've stopped it."

Added New York Gov. David Paterson: "This case clearly illustrates that the threat of terrorism in New York is persistent. ...We must remain vigilant against those who wish to do us harm."

Liza Porteus Viana is a New York city correspondent for HSToday.us who regularly covers homeland security issues.