Attorney General says suspect providing useful information.
(CNN) -- The suspect in the failed Times Square car bombing has admitted involvement in what authorities have now labeled "a terrorist plot," Attorney General Eric Holder said Tuesday.
Faisal Shahzad, a 30-year-old Pakistani-American, was arrested around 11:45 p.m. ET Monday at New York's John F. Kennedy International Airport moments before he was to fly to Pakistan via Dubai. He is to appear in federal court in Manhattan later Tuesday.
"It is clear that this was a terrorist plot," Holder said. It could have caused "death and destruction in the heart of New York City."
Shahzad was on board Emirates Airlines Flight 202 to Dubai, United Arab Emirates, when the plane was called to return to the gate, a law enforcement source said. Shahzad was booked through to Islamabad, Pakistan, via Dubai, a senior airline official confirmed.
The FBI said its agents and New York detectives then arrested Shahzad "for allegedly driving a car bomb into Times Square."
FBI Deputy Director John Pistole said that Shahzad was on the federal "no fly" list, which helped Customs and Border Protection agents to arrest him.
Holder said federal agents are continuing to question Shahzad.
"As a result of those communications, Shahzad has provided useful information to authorities. We anticipate charging him with an act of terrorism transcending national borders, attempted use of a weapon of mass destruction, use of a destructive device during the commission of another crime, as well as assorted explosives charges."
Hours after authorities arrested Shahzad, security forces in Pakistan seized two or three people in a raid in connection with the failed Times Square bombing, a Pakistani intelligence source said.
The Pakistan raid took place in a house in Karachi's Nazimabad district where Shahzad was believed to have stayed during his last visit to the country. Shahzad is a naturalized U.S. citizen of Pakistani descent.
Shahzad has a Karachi identification card, a sign of Pakistani residency, and his family is from volatile northwestern Pakistan, where government forces have been fighting Taliban militants, who have strongholds in the area, according to Pakistani Interior Minister Rehman Malik.
Meanwhile, investigators Tuesday found a 9 mm handgun with ammunition in a white Isuzu that the suspect is believed to have driven to the airport, a federal law enforcement source said.
The source also said 15 bags of "standard green fertilizer" were found in the trash outside Shahzad's Shelton, Connecticut, apartment. Also found in the trash was flash powder.
Hours after the arrest, police were at a house in a Bridgeport, Connecticut, working-class neighborhood. Agents with the FBI and local police, including members of a bomb squad, conducted a search, and investigators removed filled plastic bags.
Investigators also were combing through Shahzad's receipts, and roommates were being interviewed.
Detectives also found a hand-drawn map in the attempted bombing probe, but it's not clear where it was found, a federal law enforcement official said.
President Obama said Tuesday that "justice will be done" in the case and that U.S. officials "will do everything in our power to protect the American people."
The failed bombing is "another sobering reminder of the times in which we live," Obama told an audience of business leaders. But the United States "will be vigilant" and "will not cower in fear," he said.
Also Tuesday, New York Mayor Michael Bloomberg praised the dogged law enforcement efforts but also said the city won't tolerate any backlash against Pakistanis or Muslims.
Police have been engaged in a furious manhunt in the New York area for those responsible for an intended terrorist attack Saturday night in the heart of Manhattan's Times Square.
According to a source familiar with the investigation, the individuals didn't have the expertise to detonate a parked Nissan Pathfinder containing propane tanks, fertilizer and gasoline.
Authorities focused on Shahzad when they traced evidence to him from the sale of the Nissan Pathfinder used in the failed attack -- information considered the linchpin of the case.
The Nissan Pathfinder had its vehicle identification number removed from the dashboard. Police climbed under the SUV and retrieved the VIN from the bottom of its engine block.
This breakthrough led investigators to the vehicle's registered owner and then on to Shahzad, who purchased the SUV, an official said.
The Nissan Pathfinder was sold three weeks ago in a cash deal with no paperwork exchanged, a law enforcement source with knowledge of the investigation said Monday. The $1,800 deal was closed at a Connecticut shopping mall, where the buyer handed over the money and drove off, the source said.
Cell phone calls conducted for the purchase of the vehicle helped lead police to the suspect, law enforcement sources said.
Sources said investigators got cell phone information from the daughter of the Nissan Pathfinder owner. She sold the vehicle to Shahzad on behalf of her father.
She talked on the phone to Shahzad in organizing the purchase of the sport utility vehicle, which was advertised for sale on Craigslist.
Another law enforcement source said Shahzad claimed to have acted alone in the attempted bombing, but the Joint Terrorism Task Force has said it's considering the possibility that the attempt involved more than just a "lone wolf."
The official who released the information about the map said he believes Shahzad "wasn't working alone."
While police continued to piece together information about Shahzad, they learned he traveled to Dubai before, most recently in June 2009 and returned to the United States in early February, a law enforcement official said.
Shahzad became a U.S. citizen on April 17, 2009, a federal law enforcement source said. Because of his recent change in residency status, authorities had his picture and were able to show it to the seller of the vehicle, who identified Shahzad as the purchaser.
A woman who said she lived next door to Shahzad in Shelton said there was some kind of police activity at his former residence Monday.
Brenda Thurman said Tuesday that the man she knew was quiet and claimed to work on Wall Street.
"He would wear all black and jog at night. He said he didn't like the sunlight," Thurman said.
She said that Shahzad, his wife, two children and his wife's two sisters lived next to her for about three years, moving out in July 2009.
Shahzad's wife told Thurman then that the family was moving to Missouri. A few weeks after they left, the bank foreclosed on the property and changed the locks, the neighbor said.
Court documents reveal Shahzad purchased a house that entered foreclosure proceedings last year.
Documents from Connecticut's Milford Superior Court show that Shahzad and Huma Mian purchased a home at 119 Long Hill Ave. in Shelton in July 2004. They took out a mortgage for $218,400 from Chase Manhattan Mortgage Corp.
Last September, the mortgage company began foreclosure proceedings. As of December 14, Shahzad and Mian owed $207,837.