Officials discovered Umar Farouk Abdulmutallab's name on the Customs and Border Protection database after he boarded his Northwest flight in Amsterdam and were waiting to question him upon landing in Detroit, senior law enforcement officials told the Los Angeles Times.
The disclosure appears to show US intelligence was close to uncovering the terrorist plot, despite the barrage of criticism it has come under since Abdulmutallab, 23, failed to detonate a bomb aboard a Northwest airliner on Christmas Day.
The window in detecting a passenger as a potential threat before boarding is limited, a senior Homeland Security official said, adding that in-depth vetting only begins once the flight manifest has been generated, a few hours before takeoff.
“The people in Detroit were prepared to look at him in secondary inspection,” said a senior law enforcement official quoted by the Times.
“The decision had been made. The... database had picked up the State Department concern about this guy, that this guy may have been involved with extremist elements in Yemen ... They could have made a decision on whether to stop him from getting on the plane.”
None of the officials quoted in the Los Angeles Times provided their identities because of the ongoing investigation into the bomb plot.
Abdulmutallab was indicted today by a grand jury for attempted murder and trying to use a weapon of mass destruction aboard a US plane and could face life imprisonment.
President Barack Obama has sharply rebuked intelligence and security services for missing a series of “red flags” that could have unmasked the plot earlier.
“That's not acceptable, and I will not tolerate it,” he said in an unusual public dressing-down of the intelligence services.
The White House is expected to release an unclassified version of a report into the intelligence failures.