May 21 (Bloomberg) -- The four men arrested last night on allegations they plotted to bomb New York City synagogues and shoot down military planes were homegrown criminals with no connections to global terror groups, officials said today.

The suspects knew each other through “prison -- prison contacts for the most part,” New York City Police Commissioner Raymond Kelly said in a televised press conference in the Bronx.

The main suspect, James Cromitie, a former resident of Brooklyn, has been arrested as many as 27 times in New York City and upstate, and the others all had criminal records, had spent time in prison and had “varying levels of charges” against them, Kelly said.

“If there can be any good news from this terror scare, it’s that this group was relatively unsophisticated, infiltrated early and not connected to another terrorist group,” New York Senator Charles Schumer, a Democrat, said in a statement.

The suspects, residents of the upstate city of Newburgh, were apprehended in a sting operation about 9 p.m. yesterday in the Riverdale section of the Bronx. They were seized after planting what they believed to be bombs in cars outside the Riverdale Temple, which is a Reform synagogue, and the nearby Riverdale Jewish Center, an Orthodox synagogue, Kelly said.

Deactivated Bombs

The FBI had rendered inactive the 37-pound bombs, which contained the plastic explosive C4. After Cromitie placed the devices in two cars, officers in a small armored vehicle called a BearCat swept in, blocking the path of the suspects’ sports utility vehicle.

Officers broke the windows and took the men into custody without resistance, Kelly said. The suspects were planning to detonate the bombs with mobile phones later, he said.

“I’ve always thought of our police department’s primary job, not as first responders but as first preventers,” New York City Mayor Michael Bloomberg said at a later press conference in the Bronx. Authorities have “no evidence whatsoever” that the suspects were part of a wider plot, he said.

The men were charged with conspiracy to use weapons of mass destruction in the U.S., which carries a maximum sentence of life in prison, Acting U.S. Attorney Lev Dassin said in a statement. They are also charged with conspiracy to acquire and use anti-aircraft missiles, Dassin said.

Obama’s Challenge

The alleged terrorist plot is the most serious in the U.S. since President Barack Obama took office in January. Obama’s plan to close the Guantanamo Bay military prison has raised criticism about what will happen to as many as 240 suspected terrorists, who may have to be relocated to prisons in the U.S.

The four men planned to bomb the two synagogues and target military planes located at the New York Air National Guard base at Stewart International Airport in Newburgh, about 60 miles (97 kilometers) north of Manhattan, prosecutors said.

There are several U.S. Air Force cargo aircraft at the Air National Guard base that are used to transport military supplies and personnel to armed forces in Afghanistan and Iraq, prosecutors said.

The suspects dealt with a law-enforcement informant, who they believed was affiliated with a Pakistan-based terrorist group, Jaish-e-Mohammed, in their attempts to obtain weapons, according to the statement.

The plot began last June when the informant met Cromitie at a mosque in Newburgh, according to the complaint. Cromitie said his parents lived in Afghanistan before he was born and that he was “upset about the war there,” prosecutors said.

‘Something to America’

“Cromitie was unhappy that many Muslim people were being killed in Afghanistan and Pakistan by the United States Military forces,” according to the complaint. Cromitie expressed an interest in doing “something to America,” the complaint says.

During a trip to a Muslim conference in Philadelphia in November, Cromitie told the informant that “the best target” in New York, the World Trade Center, “was hit already” and expressed interest in destroying a synagogue, the complaint says.

In December, Cromitie asked the informant to obtain rockets and explosives for “planned operations,” according to the complaint.

This month the informant traveled with three of the defendants to a Stamford, Connecticut, warehouse, where they collected three bombs packed with plastic explosives and a Stinger guided missile, all of which had been disabled by law- enforcement officials, according to the complaint.

The other three defendants are David Williams, Onta Williams and Laguerre Payen, all of whom are listed as having one or two aliases each. All of the suspects are U.S. natives except for Payen, who was born in Haiti, Kelly said.

Religious Conversions

Three of the suspects converted to Islam, an unidentified official told the Associated Press. David Williams was introduced to the religion in prison, his aunt, Aahkiyaah Cummings, told AP.

Cromitie, 55, Onta Williams, 32, and David Williams, 28, were held following an initial appearance in U.S. District Court in White Plains today, said Herbert Hadad, a spokesman for the U.S. Attorney’s Office. Their lawyers didn’t seek bail today, Hadad said. A preliminary hearing was scheduled for June 5. Payen is due in court later today.

The case is U.S. v. Cromitie, U.S. District Court, Southern District of New York.

New York’s mayor is the founder and majority owner of Bloomberg News parent Bloomberg LP.

To contact the reporters on this story: Chris Dolmetsch in New York at cdolmetsch@bloomberg.net; Edvard Pettersson in Los Angeles at epettersson@bloomberg.net.

Last Updated: May 21, 2009 14:39 EDT