While the suspect, Abdel Hamed Shehadeh, is only charged with lying to the FBI about the purpose of his alleged travels, investigators said they believe he was an emerging terror threat.
"In sharing information developed by the NYPD's Intelligence Division with our federal partners, the Police Department worked hand in glove with the FBI to curtail an alleged terrorist threat in the making," said NYPD Commissioner Ray Kelly.
Officials said Shehadeh had traveled to Pakistan at least once in the last two years in an alleged attempt to join extremists there. They also said when he returned to the US, he went to the armed forces recruiting center in Times Square to try to sign up. His goal, officials said, was to be deployed to Iraq so he could target American soldiers there.
"Shehadeh lied about the purpose of his travel to Pakistan, then he lied in his attempt to join the US military," said NY FBI director Jan Fedarcyk. "The real purpose, it is alleged, was not to join US forces but to wage war against them."
Shehadeh was arrested in Honolulu where he now lives. Court papers said he lived much of his life on Staten Island.
Officials said he started websites that posted radical teachings of al Qaeda-linked cleric Anwar al-Awlaki and al Qaeda leader Ayman al-Zawahiri.
Investigators said they had been watching Shehadeh for more than two years and there was no immediate threat.
Arrested on false statement charges in connection with a terror matter, he could face 8 years in prison.
Attempts to find and contact Shehadeh's defense lawyer in Hawaii were not immediately successful.
On Staten Island, Shehadeh's third-cousin, who was relatively close to him, described him as a basketball-loving kid from Staten Island who never spoke about Al Qaeda or guns.
"There's only good I know about him," said Bader Suleiman, 35, who lives in the Prince's Bay section. He added that he last saw his third cousin about three years ago. "When I heard, it was a surprise, shocking for us."
Suleiman said the suspect is the middle child of five sons born in the United States to parents of Palestinian heritage. He said the father works in a supermarket and at least one of the brothers is in college.
The cousin said that Shehadeh went to Tottenville High School but an officer there said the young man did not graduate from the 5,000-student school. A bad car accident landed Shehadeh in the hospital for nearly a year when he was about 18, said the cousin.