The U.S. Customs and Border Protection agency because at least one passenger's name appeared on the government's so-called "no-fly" list, CBS News reports. An Emirates spokesperson said in a statement that two passengers were incorrectly identified and later cleared by the Transportation Security Administration.
The alert turned out to be what's being called a "false match" because the passenger just had the same name as someone on the list, CBS News reports.
The list - one of the government's most public counterterrorism tools since the Sept. 11, 2001, attacks - and the process the government uses to tell the difference between suspected terrorists and harmless passengers returned to the spotlight after the arrest of Faisal Shahzad, the man who admitted to authorities he left a car bomb in New York's Times Square.
Shahzad was able to purchase a last minute ticket late Monday night. Like Thursday's holding, the flight involved the Emirates carrier flying from Kennedy airport to Dubai. On Monday night, Emirates apparently failed to check the latest version of the terror watch list that included Shahzad's name.
Customs and Border Protection officials eventually saw Shahzad's name on the list of passengers 30 minutes before the flight was to take off. They pulled Shahzad off the plane and arrested him before the plane left the gate.
Thursday's holding of the Emirates flight wasn't the no-fly list's first case of mistaken identity and is unlikely to be its last, the possible result of the government's since the arrest of Nigerian Umar Farouk Abdulmuttalab, the man arrested for the Christmas Day attack on a Detroit-bound jet.
Current and former intelligence, counterterrorism and U.S. government officials in March provided The Associated Press a behind-the-scenes look at how the no-fly list is created. They spoke on condition of anonymity to discuss sensitive security issues.
Despite changes over time, the list remains an imperfect tool, dependent on the work of hundreds of government terrorism analysts who sift through massive flows of information. The list ballooned after Sept. 11 and has fluctuated in size over the past decade. In 2004, it included about 20,000 people. The standards for getting on the list have been refined over the years, and technology has improved to make the matching process more reliable.
There are four steps to banning a person from flying:
• It begins with law enforcement and intelligence officials collecting the smallest scraps of intelligence - a tip from a CIA informant or a wiretapped conversation.
The information is then sent to the National Counterterrorism Center, a Northern Virginia nerve center set up after the Sept. 11 attacks. There, analysts put names - even partial names - into a huge classified database of known and suspected terrorists. The database, called Terrorist Identities Datamart Enterprise, or TIDE, also includes some suspects' relatives and others in contact with the suspects. About 2 percent of the people in this database are Americans.
Analysts scour the database trying to make connections and update files as new intelligence flows in.
The next tier of analysis happens at the Terrorist Screening Center, another Northern Virginia intelligence center, staffed by analysts from federal law enforcement agencies across the government.
• About 350 names a day are sent to the Terrorist Screening Center for more analysis and consideration to be put on the government-wide terror watch list. This is a list of about 418,000 people, maintained by the FBI.
To place a name on that list, analysts must have a reasonable suspicion that the person is connected to terrorism. People on this watch list may be questioned at a U.S. border checkpoint or when applying for a visa. But just being on this list isn't enough to keep a person off an airplane. Authorities must have a suspect's full name and date of birth as well as adequate information showing the suspect is a threat to aviation or national security.
• Once armed with information for those three categories, about a half-dozen experts from the Transportation Security Administration who work at the screening center have two options. They can add a suspect to the "selectee list," a roster of about 18,000 people who can still fly but must go through extra screening at the airport. Or, if analysts determine a person is too dangerous to board a plane, they can put the suspect on the no-fly list.
The names on each list are constantly under review and updated as the threat changes.
In 2007, officials removed people who were no longer considered threats. Some were inactive members of the Irish Republican Army, a former law enforcement official said. And in 2008, the criteria was expanded to include information about young Somali-American men leaving the U.S. to join the international terrorist group al-Shabab, the senior intelligence official said. If a person on the no-fly list dies, his name could stay on the list so that the government can catch anyone trying to assume his identity.
At times, officials have allowed passengers to fly even if they are on the no-fly list, the former law enforcement official said. In some cases, this is to let agents shadow suspected terrorists while they're in the U.S. Before this happens, FBI agents and TSA experts consult with each other. If it is decided a suspected terrorist should be allowed on the flight, he and his belongings might then go through extra screening, he might be watched on camera at the airport, and more federal air marshals might be assigned to monitor him during his flight, the former official said.
Coverage of Times Square Bomb Plot
Authorities Lost Faisal Shahzad in Traffic
Shahzad: Number Cruncher to Terror Suspect
Bomb Suspect Shahzad Seen Walking Away in Video
How You End Up on the U.S. No-Fly List
Shahzad Bought Weak Fireworks, Store Owner Says
NYT: Shahzad Waives Right to Speedy Arraignment
Faisal Shahzad's Near Escape
The Pakistan Connection
Faisal Shahzad's Motive Shrouded in Mystery
"Unguided Missiles" Pose New Terrorist Threat
53 Hours from Times Square Smoking SUV to Arrest
How Close was Shahzad from Getting Away?
Shahzad's Connecticut Associates under Scrutiny